The interpretation timeline
Galatians 1:9 Douay-Rheims

As we said before, so now I say again: If any one preach to you a gospel, besides that which you have received, let him be anathema.

A.D. 407 – 1871 6 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“"But though we, or an angel from heaven, should preach unto you any Gospel other than that which we preached unto you, let him be anathema." See the Apostle's wisdom; to obviate the objection that he was prompted by vainglory to applaud his own doctrine, he includes himself also in his anathema; and as they betook themselves to authority, that of James and John, he mentions angels also saying, "Tell me not of James and John; if one of the most exalted angels of heaven corrupt the Gospel, let him be anathema." The phrase "of heaven" is purposely added, because priests are also called angels. "For the priest's lips should keep knowledge, and they should seek the law at his mouth: for he is the messenger [angel] of the Lord of hosts." Lest therefore it should be thought that priests are here meant, by the term "angels," he points out the celestial intelligences by the addition, "from heaven." And he says not, if they preach a contrary Gospel, or subvert the whole of the true one, let them be anathema; but, if they even slightly vary, or incidentally disturb, my doctrine. "As we have said before, so say I now again." That his words might not seem to be spoken in anger, or with exaggeration, or with recklessness he now repeats them. Sentiments may perhaps change, when an expression has been called forth by anger, but to repeat it a second time proves that it is spoken advisedly, and was previously approved by the judgment. When Abraham was requested to send Lazarus, he replied, "They have Moses and the Prophets; let them hear them: if they hear them not, neither will they be persuaded, if one rise from the dead." And Christ introduces Abraham thus speaking, to show that He would have the Scriptures accounted more worthy of credence, even than one raised from the dead: Paul too, (and when I say Paul, I mean Christ, who directed his mind,) prefers them before an angel come down from heaven. And justly, for the angels, though mighty, are but servants and ministers, but the Scriptures were all written and sent, not by servants, but by God the Lord of all. He says, if "any man" preach another Gospel to you than that which we have preached,-not "if this or that man:" and herein appears his prudence, and care of giving offence, for what needed there still any mention of names, when he had used such extensive terms as to embrace all, both in heaven and earth? In that he anathemized evangelists and angels, he included every dignity, and his mention of himself included every intimacy and affinity. "Tell me not," he exclaims, "that my fellow-apostles and colleagues have so spoken; I spare not myself if I preach such doctrine." And he says this not as condemning the Apostles for swerving from the message they were commissioned to deliver; far from it, (for he says, whether we or they thus preach;) but to show, that in the discussion of truth the dignity of persons is not to be considered.”
Source

Scholastic

c. 1100 – 1500
1273
A.D.
Thomas Aquinas Catholic
1225–1274
“Above, the greeting came first; in what follows, the epistolary narrative follows, in which the Apostle argues against their error. Second, he admonishes them to correction, in chapter 5, where he says stand fast therefore, and so on. Now he argues against their error in two ways: both through the authority of the evangelical teaching, and through the reasoning of the Old Testament, in chapter 3, where he says O foolish, and so on. He argues against their error, then, by showing the authority of the evangelical teaching. First by showing their own fickleness as regards the light dismissal of the evangelical teaching; second by commending the authority of that evangelical teaching itself, so that the more worthy what they are dismissing is shown to be, the greater their error appears — where he says for I make known to you, and so on. Concerning the first he does two things. First he aggravates the fault; second he inflicts the penalty, where he says but though we, and so on. Now he aggravates the fault both of those who are being led astray and of those who are leading them astray, where he says unless there are some, and so on. Concerning the first he does three things. First he aggravates the fault of those being seduced from the fickleness of their mind. Hence he says I marvel — as if to say: since you know how many good things have been said to have come to you through Christ, and that although you were so well instructed by me, nevertheless so, that is, to such an extent and so vehemently, that you seem already to have forgotten, so soon, that is, in so short a time, you are removed — so as to play on the name; for Galatia is said to mean "removal" or "translation." As if to say: you are Galatians, because you are removed so quickly. Ecclesiasticus 19:4: he who believes quickly is light of heart. Second, he aggravates their fault from that which they left. For if reason withdraws and is transferred away from evil, it is commendable and does well; but when it withdraws from the good, then it is culpable. And thus these men had been transferred away from the good. And therefore he says to them: and if it is to be marveled at that you are removed so quickly and thus, he nevertheless adds matter for wonder, namely that you are removed from him, that is, from God, and from his faith, who called you into the grace of Christ, that is, into participation in the eternal good, which we have through Christ. 1 Peter 2:9: giving thanks to God, who has called you into his wonderful light. Likewise 2 Peter 2:21: it would have been better for them not to have known the way of truth, than, and so on. Third, he aggravates their fault from that to which they have been turned, because they have not been turned to the good, but to evil. Hence he says unto another gospel, that is, of the old law, which is a good annunciation insofar as it announces certain goods, namely temporal and carnal ones. Isaiah 1:9: if you be willing and will hearken to me, and so on. But nevertheless it is not perfect and simply so, as the Gospel is; because it does not announce perfect and greatest goods, but small and least ones. But the new law is perfectly and simply the Gospel, that is, a good annunciation, because it announces the greatest goods, namely heavenly, spiritual, and eternal ones. And although it be another gospel according to the tradition of the false apostles, nevertheless according to my preaching it is not. For it is other in its promises, but it is not other in its figure, because the same thing is contained in the Old Testament and in the New: in the Old indeed as in figure, in the New indeed as in the reality and expressly. And thus it is another gospel as regards those things which appear outwardly, but as regards those things which are within and are contained, it is not other. But although it is not other in itself, nevertheless it can become other through the fault of others, namely of those who are leading astray. And therefore, aggravating their fault, he says unless there are some, namely seducers, who trouble you, that is, who becloud the purity of your understanding, with which you had been imbued through the truth of the faith. Because, although the same thing is contained as regards the inner understanding through the Old and New Testament, as has been said, nevertheless if after the reception of the New Testament the Old is repeated, it seems to be shown that the New is not perfect, and that the one is other than the other. And therefore he says that it is not other, unless there are some, etc., because these false apostles, after the reception of the evangelical faith, were compelling them to be circumcised, showing through this that circumcision is something other than Baptism and effects something that Baptism cannot effect, and therefore these men are troubling you. Below, 5:12: I would that they were even cut off who trouble you, and so on. And they truly trouble you, because they wish to convert the Gospel of Christ, that is, the truth of the evangelical teaching into the figure of the law, which is absurd and the greatest disturbance. For a thing ought to be converted into that toward which it is ordered; but the New Testament and the Gospel of Christ is not ordered toward the Old, but rather on the contrary the old law is ordered toward the new law, as figure toward truth; and therefore the figure ought to be converted into the truth, and the old law into the Gospel of Christ, but not the truth into the figure, nor the Gospel of Christ into the old law: which is clear from the very usage of speech. For we do not say that a man is like the image of a man, but rather the other way around, the image is like the man. Jeremiah 15:9: they themselves shall be turned to thee, etc.; and Leviticus 26:10: new things coming upon you, and so on. Consequently, after the aggravation of the fault, the infliction of the penalty is set down, when he says but though, and so on. And concerning this he does two things. First he promulgates the sentence; second he assigns the reason for the sentence, where he says for do I now persuade men, and so on. Concerning the first he does two things. First he shows the authority of his sentence; second he pronounces it, where he says as I have said before, and so on. Now he shows that the authority of his sentence is great, in that it would have efficacy not only against perverters and against seducers who are subjects, but even against equals, such as the other apostles are, and even against superiors, such as the Angels are, if they were guilty of this crime, namely of converting the Gospel into the old law. And therefore he says: for the authority of our sentence which I promulgate (which is excommunication) has efficacy not only against those who intend such things, but though we, namely the apostles, or an angel, good or bad, coming from heaven should preach a gospel besides that which has been preached by us, let him be anathema, that is, he shall be guilty of this sentence, which we promulgate. Now for the evidence of what has been said, three things must be inquired into. First, what this word "anathema" signifies. Concerning which it must be known that anathema is a Greek word, and it is compounded from ana, which is "up" or "upward," and thesis, "a positing," as it were "a placing on high." And it arose from a certain ancient custom. For the ancients, when they fought, would sometimes seize some plunder from the enemies, which they did not wish to convert to their own use, but they would hang it up in temples, or in some public place of the city, as it were set apart from the common use of men, and the Greeks called every such thing thus hung up anathema; and from this the custom grew up, that everything which was excluded from common use was said to be anathematized. Hence it is said in Joshua 6:17 concerning Jericho and all the things that are in it, that Joshua straightway anathematized them. And therefore this also grew up in the Church, that those who are excluded from the common fellowship of the Church, and from participation in the sacraments of the Church, are said to be anathematized. Second, the reason must be inquired into of what he says though we or an angel, and so on. Here it must be known that there is a threefold teaching. The first is that of the philosophers, who by the guidance of their own reason arrived at the knowledge of their teaching. There is another teaching, which is handed down through Angels, as the old law is. For the law was not brought forth by human will (as is said at Galatians 3:19), but through Angels in the hand of a mediator, as is said below at 3:19. But there is a certain teaching handed down by God immediately, as the teaching of the Gospel is. John 1:18: no man hath seen God at any time, and so on. Hebrews 1:2: in these last days hath spoken to us by his Son. And afterward: which having received a beginning, and so on. Therefore the teaching which is handed down through a man can be changed and revoked through another man who knows better, just as one philosopher refutes the sayings of another; likewise through an Angel who sees the truth more keenly. Also the teaching which is handed down through an Angel could perhaps be removed through another, superior Angel, or through God. But on the other hand the teaching which is handed down immediately by God cannot be made void either through a man or through an Angel. And therefore if it should happen that a man or an Angel should say something contrary to that which has been handed down by God, his own statement is not against the teaching, so as through this to be made void and rejected, but rather the teaching is against him, because he who speaks it ought to be excluded and rejected from the communion of that teaching. And therefore the Apostle says that the dignity of the evangelical teaching, which is handed down immediately by God, is of such great dignity, that whether a man or an Angel should preach a gospel other than that which has been preached in it, he is anathema, that is, he is to be cast out and rejected. Third, it is necessary to resolve the objections which occur concerning this. Of which one is: since an equal does not have authority over an equal, and much more does not have it over a superior, it seems that the Apostle could not excommunicate the apostles who were his equals, and still less the Angels who are superiors. Matthew 11:11: he that is the lesser in the kingdom of heaven is greater than he. Therefore it is not anathema through this. To this it must be said that the Apostle uttered this sentence, not by his own authority, but by the authority of the evangelical teaching, of which he was the minister, of which teaching the authority is such that whoever speak against it are to be excluded and rejected. John 10: the word that I have spoken, the same shall judge him in the last day, and so on. Another question is, because he himself says besides that which has been preached. Therefore no one ought to teach, or to preach, except what is written in the epistles and in the Gospel. But this is false, because it is said at 1 Thessalonians 3:10: that we may accomplish those things that are wanting to your faith, and so on. I respond. It must be said that nothing else is to be preached as gospel, than that which is contained in the Gospels, and in the epistles, and in sacred Scripture, implicitly or explicitly. For sacred Scripture and the Gospel preach that Christ is to be believed in explicitly. Hence whatever is contained in them implicitly, which serves toward his teaching, and toward the faith of Christ, can be preached and taught. And therefore when he says besides that, etc., that is, adding something wholly foreign. Apocalypse, at the end: if any man shall add to these things, or shall add, namely something wholly foreign, God shall add unto him the plagues written in this book. And Deuteronomy 4: you shall not add anything, etc., namely contrary or foreign, neither shall you take away, and so on. Consequently, when he says as I have said before, etc., he pronounces his sentence in respect of evil, saying: as I have said before concerning Angels and apostles, I say the same concerning the seducers. If any seducer shall preach a gospel besides that which you have received from me, let him be anathema, that is, excommunicated. And this is the sentence which he pronounces. But are all heretics excommunicated by this? It seems not, because it is said at Titus 3:10: a man that is a heretic, after the first and second admonition, avoid, and so on. I respond. It must be said that someone can be called a heretic either because he simply errs out of ignorance, and from this he is not excommunicated; or because he errs out of obstinacy and strives to pervert others, and then he incurs the canon of a sentence already passed. But whether from that time he pronounced sentence against heretics by these words is doubtful, since nevertheless sentence has already been passed against heretics in the Councils. It can nevertheless be said that perhaps here they are shown to be worthy of excommunication. Consequently, when he says for do I now persuade men, etc., he shows the reason for the sentence. Here first he sets down the reason for the sentence itself; second he here makes clear his purpose, where he says or do I seek, and so on. For someone could say: why do you excommunicate in this way? Perhaps some are friends, or persons of some authority, therefore it ought not to be done thus. Therefore the Apostle, responding, says: nay rather, it ought to be done thus, because these things which I now say are not for the favor of men, but that I may please God, and this is what he says for do I now, that is, after my conversion, or in this epistle, persuade men, that is, does my desire tend to this, that I might please men, or God? As if to say: these things which I do, I do for this reason, that I may please God alone. 1 Thessalonians 2:4: we speak not as pleasing men, but God, and so on. Nor indeed do we speak by the authority of men, but by the divine authority. But that I do not intend to please men is clear from my intention and from my purpose. For I do not seek to please men, that is, it is not of my intention to convert men, that I may please men only, but for the honor of God. And this is clear, because if I still intended to please men, as I once pleased them, I should not be the servant of Christ. The reason for which is that these things are contrary to one another. To this extent, namely, that I should wish to please men for the sake of men, not referring that to God. For if I should intend at some time to please men for this reason, that I might draw them to God, I do not sin. But if in the first way, I am not the servant of Christ. Isaiah 28:20: the bed is straitened, so that one must fall out, and so on. Matthew 6:24: no man can serve two masters, and so on. Psalm 52:6: they are confounded that please men.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“As we have said before, so say I now again,.... Either when he first preached the Gospel among them; or rather referring to what he had just now said, which he repeats with some little alteration; as if any, men, or angels, be they of what name, figure, rank, or office whatever, preach any other Gospel unto you, than that ye have received; and as the apostle thought, readily, willingly, sincerely, and heartily, in the love of it; assenting to the truth, feeling the power of it, and openly professing it: let him be accursed; which he repeats, for the more solemn asseveration and confirmation of it; and to show that this did not drop from his lips hastily and inadvertently; nor did it proceed from any irregular passions, or was spoken by him in heat, and in an angry mood, his mind being ruffled, disturbed, and discomposed; but was said by him in the most serious and solemn manner, upon the most thoughtful and mature consideration of the affair.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“Let him be accursed - Perhaps this is not designed as an imprecation, but a simple direction; for the word here may be understood as implying that such a person should, have no countenance in his bad work, but let him, as Theodoret expresses it, Αλλοτριος εστω του κοινου σωματος της εκκλησιας, be separated from the communion of the Church. This, however, would also imply that unless the person repented, the Divine judgments would soon follow.”
Source
1849
A.D.
1774–1849
“The terrible sentence awarded by St. Paul, bears equally strong against modern as against ancient innovators in religion.”
1871
A.D.
1871
“said before--when we were visiting you (so "before" means, Co2 13:2). Compare Gal 5:2-3, Gal 1:21. Translate, "If any man preacheth unto you any gospel BESIDE that which," &c. Observe the indicative, not the subjunctive or conditional mood, is used, "preacheth," literally, "furnisheth you with any gospel." The fact is assumed, not merely supposed as a contingency, as in Gal 1:8, "preach," or "should preach." This implies that he had already observed (namely, during his last visit) the machinations of the Judaizing teachers: but his surprise (Gal 1:6) now at the Galatians being misled by them, implies that they had not apparently been so then. As in Gal 1:8 he had said, "which we preached," so here, with an augmentation of the force, "which ye received"; acknowledging that they had truly accepted it. accursed--The opposite appears in Gal 6:16.”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.