The interpretation timeline

2Tim 2:19

How this passage has been read — the sources, oldest to newest.

From the early Church Fathers to now.

16 Patristic · 1 Orthodox · 1 Medieval · 1 Catholic

2Tim 2:19 · Douay-Rheims
“But the sure foundation of God standeth firm, having this seal: the Lord knoweth who are his; and let every one depart from iniquity who nameth the name of the Lord.”
Patristic before A.D. 750
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“You are human, and so you know other people only from the outside. You think as you see, and you see only what your eyes let you see. But "the eyes of the Lord are lofty." "Man looks on the outward appearance, God looks on the heart." So "the Lord knows those who are his." He roots up the plant which he has not planted in his garden. He shows the last to be first. He carries a fan in his hand to purge his floor. Let the chaff of cheap faith fly away as it pleases before every wind of temptation. So much the purer is the heap of wheat which the Lord will gather into his barn.”
Source
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“"The Lord (beholdeth and) knoweth them that are His; " and "the plant which (my heavenly Father) hath not planted, He rooteth up; " and "the first shall," as He shows, "be last; " and He carries "His fan in His hand to purge His threshing-floor.”
220
A.D.
Tertullian Patristic
c. A.D. 150–220
“To meet these its counsels, do you apply the examples of sisters of ours whose names are with the Lord, -who, when their husbands have preceded them (to glory), give to no opportunity of beauty or of age the precedence over holiness.”
254
A.D.
Origen Patristic
c. A.D. 184–253
“God ignores those who are alienated from him.… We say these things, however, not thinking anything blasphemous about God … not ascribing ignorance to him, but thus we understand that these whose activity is considered unworthy of God are also considered to be unworthy of knowledge of God. For God does not deign to know him who has turned away from him and does not know him.”
Source
254
A.D.
Origen Patristic
c. A.D. 184–253
“Those who have been made one with and united with something know that with which they have been made one and have been united. Yet before such unity and participation, even if they objectively grasp something of the explanations given about a thing, they still do not know it.… For, in our view, the Lord has known those who are his because he has been made one with them and has given them a share of his own divinity and has taken them up, as the language of the Gospel says, into his own hand, since those who have believed in the Savior are in the Father's hand. For this reason also, unless they fall from his hand—thereby removing themselves from the hand of God, they will not be snatched away, for no one snatches anyone from the Father's hand.”
Source
373
A.D.
Athanasius of Alexandria Patristic
c. A.D. 296–373
“Faith and godliness, you see, are so closely allied that they can be considered sisters. Anyone who believes in the Lord is godly, and the person who is godly believes all the more. On the other hand, one who is in a state of wrong relationships will certainly wander from the faith, and one who falls from godliness falls from the true faith. Paul, recognizing this, advised his disciples: "Avoid profane conversations, for they lead people further into ungodliness." That is why the Ariomaniacs, being enemies of Christ, have left the church. They have dug a pit of unbelief into which they themselves have fallen.… The apostle Paul's words against Philetus and Hymenaeus stand as a warning against ungodliness such as that of the Arians: "God's foundation is firm, bearing this seed: 'The Lord knows his own people' and 'Let everyone who names the name of the Lord depart from iniquity.' "”
Source
397
A.D.
Ambrose of Milan Patristic
A.D. 339–397
“The Lord considered and knew those that were His, and drew His saints to Himself; and those whom He chose not, He did not draw to Himself.”
397
A.D.
Ambrose of Milan Patristic
A.D. 339–397
“Raise your mind's footsteps to the things that are to come, and you will find there the wicked one who you thought was here will not be, for he does not exist who is nothing. Finally, the Lord knows those who are his own; but those who are not, he does not know, because they have not recognized him who is.”
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“"Nevertheless," he says, "the foundation of God standeth sure, having this seal, The Lord knoweth them that are His. And, Let every one that nameth the name of the Lord depart from iniquity." He shows that even before they were subverted, they were not firm. For otherwise, they would not have been overthrown at the first attack, as Adam was firm before the commandment. For those who are fixed not only are not harmed through deceivers, but are even admired. And he calls it "sure," and a "foundation"; so ought we to adhere to the faith; "having this seal, The Lord knoweth them that are His." What is this? He has taken it from Deuteronomy; that is, Firm souls stand fixed and immovable. But whence are they manifest? From having these characters inscribed upon their actions, from their being known by God, and not perishing with the world, and from their departing from iniquity. "Let every one," he says, "that nameth the name of the Lord depart from iniquity." These are the distinguishing marks of the foundation. As a foundation is shown to be firm, and as letters are inscribed upon a stone that the letters may be significant. But these letters are shown by works, "Having," he says, "this seal" fixed thereon, "Let every one that nameth the name of the Lord depart from iniquity." Thus if any one is unrighteous, he is not of the foundation. So that this too is of the seal, not to do iniquity.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“It is the elect who are meant in the letter to Timothy, where, after mention of the attempts of Hymenaeus and Philetus to undermine the faith, the text goes on, "But the sure foundation of God stands firm, bearing this seal: 'The Lord knows who are his.' " The faith of these latter, which works through charity, either does not ever fail, or, if it fail in some, the loss is repaired before death, the sin that intervened is blotted out and perseverance to the end is granted. On the other hand, those who are not to persevere to the end, those who are to fall from Christian faith and conduct, in such a way that the end of this life will find them thus fallen—these men are certainly not to be counted in the number of the elect, not even at the time during which they are living in goodness and piety.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“The abundance of bad people in the world is the big heap of stuff needed for refining the good. Although the good can't be seen, mixed up in the vast multitude of the bad, the Lord knows who are his own. Under the hand of such a great craftsman, the speck of gold cannot get lost in the huge pile of straw. How much straw is there, how little gold! But have no fear: the craftsman is so great that he can refine it and cannot lose it.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“Something is always going on in this olive press. The world is the press; there is no end to its pressures. Be oil, not dregs. Let each of you be converted to God and change your manner of life. The oil goes by hidden channels to its own secluded vats. Others sin, mock, blaspheme, make loud accusations in the streets—the dregs are oozing out. Yet the Lord of the press does not cease from operating it through his workmen, the holy angels. He knows his oil; he knows how much it can take, the exact pressure needed to squeeze it out. "The Lord knows," you see, "who are his own." Avoid the dregs. They are murky, out in the open for all to see.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“And we know that the apostle said of the vessels placed in the great house, "If a man therefore purge himself from these, he shall be a vessel unto honor, sanctified and ready for the Master's use, and prepared for every good work." But in what manner each man ought to purge himself from these he shows a little above, saying, "Let everyone that names the name of Christ depart from iniquity." This is so that he may not in the last day be blown away with the chaff from the threshing floor. Nor may he be separated at the last by hearing the command, "Depart from me, you that work iniquity."”
Source
533
A.D.
Fulgentius of Ruspe Patristic
c. A.D. 468–533
“He therefore will attain life who keeps the commandments. But who keeps the divine commandments except the one who, converted to God before the end of this present life, has departed from his earlier sins? So the blessed Peter warns us, "Let everyone who calls upon the name of the Lord avoid evil." He said this, knowing that penance is done fruitfully in this present world in which forgiveness is given to penitents. But in the future world the penitence of the wicked will bear no fruit because there will be no conversion of the wicked. They will be sent into the exterior darkness where there will be wailing and the gnashing of teeth.”
Source
202 years pass — nothing from this stretch is hosted yet
735
A.D.
Bede Patristic
A.D. 673–735
“This statement of the Lord … can also be understood mystically with regard to the choosing of the spiritual Israel, that is, the Christian people, since the Lord mercifully deigned to see them when they did not yet see him, when they had not yet been called by his apostles to the grace of faith, but they were still concealed under the covering of oppressing sin.… And sometimes in the Scriptures, to be sure, the fig tree suggests the sweetness of divine love.… Those placed under it can be his elect even when they do not yet recognize the grace of their election—just as the Lord saw Nathanael when he was situated under the fig tree though Nathanael did not see him. For the Lord knows who are his, and the very name Nathanael is most suitably appropriate to their salvation. For Nathanael is interpreted "gift of God."”
Source
391 years pass — nothing from this stretch is hosted yet
Scholastic c. 1100 – 1500
1126
A.D.
Theophylact of Ohrid Orthodox
c. 1055–1107
“Here is what the apostle says: not all were led astray, but the unsteady ones. And if they had not been such, they would not have fallen away either. Just as Adam too was not firm before the temptation. Those perfectly inspired in the faith stand firm and immovable. And notice, he says "firm," and: "foundation." Thus we ought to hold fast to the faith. That is, just as inscriptions are carved on a stone, so too in his very deeds are imprinted the signs that point to him, namely: "the Lord knows" and so forth. That is, these people or such souls are foreknown by God as belonging entirely to Him, and are fore-chosen so that they would not be led astray together with the weaker ones. By "unrighteousness" the apostle means either error in doctrines or injustice in general. He who acts unjustly has no foundation, does not belong to God. For how can he belong to God, when God is righteous? He does not have the seal. Consider: if he who names the name of the Lord must depart from unrighteousness, then he who does not depart is unworthy to name His name. For praise is not fitting in the mouth of a sinner.”
Source
1274
A.D.
Bonaventure Medieval
c. A.D. 1221–1274
“And Paul says of it: "You too, were sealed with the Holy Spirit of the promise." Through this seal, the friends are distinguished from the enemies, free men from slaves, heavenly men from the earthly. This seal is imprinted on the forehead of the contemplative soul and on the foreheads of the elect. This seal was imprinted on those standing upon Mount Sion. In the Second Epistle to Timothy, it is written: "The sure foundation of God stands firm." This is the seal by which "the Lord knows who are His." He knows through an express seal through which the soul calls upon the name of the Lord out of its inner depths.”
Source
1274
A.D.
Thomas Aquinas Catholic
1225–1274
“But the sure foundation of God stands: he shows how heresies do not altogether subvert the faith. For these foundations are the persons to whom is given the grace to stand immovable: for it was founded upon a rock (Matt 7:25); it stands firm, because it cannot be moved. Hence Matthew first said: and the rain fell and the floods came and the winds blew and they beat upon that house: and it fell not (Matt 7:25). Its firmness depends, first of all, on God's predestination; second, on our free will. Hence in regard to the first he says: this sure foundation having this seal, i.e., this is the sign of its firmness: he that has received his testimony has set to his seal that God is true (John 3:33). And this is the first part of the seal, namely, from divine predestination, for the Lord knows who are his: I know my sheep, and other sheep I have that are not of this fold (John 10:14); I know you not (Matt 7:23). But as to the second he says, let everyone depart from iniquity, who names the name of the Lord. As if to say: they are so predestined by God as to be saved by their free will: because one shows that he is predestined, if in the end he does not adhere to sin. And he mentions two things which pertain to those predestined to be saved: first, they confess the faith; hence he says, everyone who names the name of the Lord: but with the mouth, confession is made unto salvation (Rom 10:10); second, that they withdraw from sin: not everyone that says to me, Lord, Lord, shall enter the kingdom of heaven (Matt 7:21). Hence he says, let everyone depart from iniquity: let the wicked forsake his way (Isa 55:7). But the fact that he says, who names the name, must be understood not of orally naming, but inwardly by faith and outwardly by good works.”
Source
Undated date unknown
Apostolic Constitutions
c. A.D. 380
“Wherefore, O bishop, when you are to go to prayer after the lessons, and the psalmody, and the instruction out of the Scriptures, let the deacon stand nigh you, and with a loud voice say: Let none have any quarrel with another; let none come in hypocrisy; that if there be any controversy found among any of you, they may be affected in conscience, and may pray to God, and be reconciled to their brethren. For if, upon coming into any one's house, we are to say, "Peace be to this house," like sons of peace bestowing peace on those who are worthy, as it is written, "He came and preached peace to you that are nigh, and them that are far off, whom the Lord knows to be His," much more is it incumbent on those that enter into the Church of God before all things to pray for the peace of God. But if he prays for it upon others, much more let himself be within the same, as a child of light; for he that has it not within himself is not fit to bestow it upon others.”
Source
Oecumenius Patristic
c. A.D. 550
“Yet the solid foundation of God stands firm, having this seal: The Lord knows those who are His. And, let everyone who names the name of the Lord depart from iniquity. Yet the solid foundation. Indeed, the faith of the weak is subverted; "a solid foundation", however, stands (referring to the faithful who cannot be overthrown), having this mark and sign: The Lord knows those who are His. Once indeed they were foreknown as wholly devoted to God and unchangeable. For the sign that they are known by God is that they could not be overthrown by wickedness so as to depart from the faith. depart from iniquity. Here is another indication: namely, let everyone who calls upon the name of the Lord depart from iniquity, that is, from the error of doctrines, as it is proper to call upon His name. For those who, like certain living columns, remain immovable, bear these inscriptions in their works.”
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.