The interpretation timeline
Isaiah 56:4 Douay-Rheims

For thus saith the Lord to the eunuchs, They that shall keep my sabbaths, and shall choose the things that please me, and shall hold fast my covenant:

1105 – 1875 7 witnesses

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
“and hold fast Heb. וּמַחֲזִיקִים, and hold fast.”
1167
A.D.
Ibn Ezra Jewish
1089–1167
“That keep my sabbath, etc. The sabbath is mentioned, because it is a sign of the covenant between Him and those that keep it, on account of God having rested on it; he who keeps the Sabbath is, therefore, a worshipper of the Lord.”
1256
A.D.
Thomas Aquinas Catholic
1225–1274
“Thus says the Lord. Here, after he had promised liberation from evils, he begins to promise salvation in the conferring of goods. And it is divided into three parts. In the first is set down the preparation for salvation; in the second, the promise of salvation, chapter 60: Arise, be enlightened; in the third, the great discernment of the salvation conferred, chapter 63: Who is this. The first into two. In the first is set down the preparation on the part of the one receiving salvation; in the second, on the part of the one saving, chapter 59: Behold, it is not shortened. The first into two. In the first he gives the wholesome counsel of preparation; in the second he excludes the vain remedy, chapter 58: Cry, cease not. The first into two. In the first he sets down the diversity of those who receive the counsel, as regards the establishment of rewards; in the second, as regards the escape from dangers, chapter 57: the just man perishes. The first into three. In the first he sets down the counsel; in the second, the fruit of the counsel in those who receive it, Blessed is the man who does; in the third, the failure of salvation in those who despise it, all you beasts. Concerning the first he does two things. First he counsels the due preparation: keep judgment, you prelates, whose office it is to judge; do justice, you subjects, that is, every virtue, according as one is conformed to another by the precepts of the law. Micah 6: I will show you, O man, what is good. Second he promises the nearness of salvation: for near, that is, close, is my salvation, because you will be saved by me after the captivity, and my justice, as regards the enemies of whom I will avenge you. Above, 46: I have brought my justice near. Blessed is the man. Here he sets down the fruit of the counsel in those who receive it: and first he sets down its usefulness, setting down the fruit of fulfillment: blessed is the man who does, fulfilling in deed, who lays hold, vigorously undertaking. Psalm 111: blessed is the man who fears the Lord; and the manner of fulfilling, as regards ceremonial matters, keeping the sabbath: for the observance of the sabbath was moral as regards this, that rest is placed in God, and that one is at some time free for divine things by abstaining from other things; but it was ceremonial as regards the determination of the time. Now the seventh day was determined for them on account of the work of creation, than which nothing more worthy had yet preceded. For us, the first day, or the eighth, on account of the mystery of the resurrection, by which nature once founded is repaired for the better. Exodus 20: remember to keep holy the sabbath day. Jeremiah 17: keep your souls. And as regards moral matters, keeping the hands. Psalm 25: I will wash my hands among the innocent. Second he sets down the universality of its usefulness, and let him not say: and first he excludes the despair of certain ones who seemed unworthy, whether on account of a defect of lineage, because they were not of the race of Israel. Who adheres, keeping his precepts. By separation, not making me a partaker of the salvation promised to them. Romans 10: for there is no distinction of Jew and Greek: for the same is Lord of all. Or on account of a defect of the generative power: and let not the eunuch say: a dry tree, powerless to beget, as a dry tree is powerless to sprout. Proverbs 11: the just, like a flourishing leaf. Second he sets down the promise: for thus says the Lord. And first to them specially, as regards the eunuchs: they shall have kept, as regards the worship of religion; they shall have chosen, as regards obedience to the law; they shall have held fast, as regards the observance of the promise of abstaining from evils: within the walls, that is, a dwelling within the walls of my city; a better name, in that they shall be called my servants and holy ones; and than sons, as if they had begotten many sons. Wisdom 3: the eunuch who has not wrought. And as regards the strangers: and to sons, that is, I will give the privileges in which the Jews glory, that they may worship, as regards special worship, and love, as sons, that they may be as servants, and glory in his dominion. Above, 19: they shall worship the Lord. And these things indeed were fulfilled in the return of the people from the captivity; but more fully in the conversion of the nations to the faith of Christ, as the Gloss explains. Second, as regards all in general: every one who keeps. And concerning this he does two things. First he sets down the promise, by which he promises the restoration of the sacred place: to the holy mountain. Namely, as above, 1: come, let us go up to the mountain of the Lord. And as regards the acceptance of sacrifices: holocausts. Malachi 3: the sacrifice of Judah and Jerusalem shall be pleasing to God. Second he sets down the order of fulfillment: and first as regards the veneration of the temple: for my house. 2 Maccabees 3: the temple throughout the whole. John 2 and Matthew 21: my house shall be called a house of prayer. Second, as regards the gathering of the people: says the Lord, to him; he gathers Israel, the nations adhering to him. Psalm 146: the Lord, building up Jerusalem, will gather the dispersions of Israel. Note on that word, and I will give a better name, that the saints have a name, first from predestination. Above, 49: the Lord has called me from the womb; second, from divine attainment. 1 John 3: behold what manner of love or charity God the Father has given us, that we should be called, and should be, sons of God. Third, from the infusion of grace. Apocalypse 2: you have a name, and you hold my name. Fourth, from the renewal of the mind. In the same place, Apocalypse 2: I will give a stone. Also note, that the name of God is to be loved: first, because it is great, so as to be feared. Malachi 1: my name is great among the nations, says the Lord. Second, because it is holy, so as to be venerated. Luke 1: he who is mighty has done great things for me, and holy is his name. Third, because it is sweet, so as to be meditated upon. Above, 26: your name and your memorial are in the desire of the soul. Fourth, because it is abundant, so as to show mercy. Canticle 1: your name is oil poured out. Fifth, because it is efficacious, so as to obtain. John 15: whatsoever you shall ask the Father in my name, he will give you. Sixth, because it is powerful, so as to save. Acts 4: there is no other name under heaven whereby we must be saved. Seventh, because it is hidden, so as to be known. Proverbs 30: what is his name. All you beasts of the field. Here he threatens those who despise it with the failure of salvation: and first he designates the punishment of slaughter: all beasts, to devour, their corpses. Ezekiel 39: speak to every bird, to all. Second he sets down the fault: and first, of the prelates, as regards their failure in government and in foreseeing dangers. Watchmen: for prelates are set up to guard the people from dangers, as a watchman guards against enemies: they have not known, to foresee dangers. Matthew 15: let them alone: they are blind leaders of the blind. In the correction of vices, all of them dogs. To bark, against vices. Psalm 37: but I, as a deaf man, heard not, and as a dumb man, not opening his mouth. In the admonition of things to be done, seeing vain things, promising them prosperous things when adverse things were imminent; and thus nourishing them in sins. Ezekiel 22: her prophets daubed them. In the plundering of goods, and most shameless dogs; as if, without any restraint of shame, despoiling their subjects of their goods, and never satisfied. Psalm 58: they shall suffer hunger like dogs. And as regards their failure in the perfection of knowledge: they, the shepherds, understanding, of the law and the prophets. Proverbs 1: the intelligent man shall possess the helm. Psalm 81: they have not known nor understood; they walk on in darkness. Second, the fault of the subjects, or of all in common: and first, as regards their own will, which pertains to pride: all, into his own way. Jeremiah 16: every one walks. Second, as regards their covetousness, which pertains to avarice: every one. Jeremiah 6: from the least even to the greatest, all are given to avarice. Third, as regards pleasure, which pertains to the concupiscence of the flesh: come. And it shall be; that is, if today we rejoice in such things, tomorrow much more. Above, 22: and behold joy and gladness, killing calves and slaying rams, eating flesh and drinking wine.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“For thus saith the Lord unto the eunuchs that keep my sabbaths,.... That fear and serve the Lord; religiously observe all times of divine worship, and walk in all the commandments and ordinances of the Lord; show regard to all the institutions of the Gospel, and perform all religious exercises, private and public, on Lord's days, and at other times: and choose the things that please me; who do that which is wellpleasing unto God, which he has declared in his word to be acceptable to him; and do that from right principles, with right views, and of choice; not forced to it by those who have authority over them, or led to it merely by example and custom: and take hold of my covenant; not the covenant of circumcision, as Kimchi; for what had eunuchs to do with that? but the covenant of grace, the everlasting covenant, the covenant of peace before spoken of Isa 14:10, made between the Father and the Son, on account of the elect; which may be said to be taken hold of when a person by faith claims his interest in God as his covenant God; comes to Christ as the Mediator of the covenant; and deals with his blood, righteousness, and sacrifice, for pardon, justification, and atonement; regards all the promises and blessings of the covenant as belonging to him and lives by faith on them, as such; so David by faith laid hold on this covenant, Sa2 23:5.”
Source
1849
A.D.
1774–1849
“Eunuchs. It was ignominious to have no children among the Jews, as the propagation of the true religion depended much on their numbers. But now, since the Church is gathered from all nations, virginity is preferable to marriage, and those who keep the sabbath, or all the commandments, and choose this state freely, will receive greater glory than the other sons and daughters of God. Against this plain meaning, P. Martyr (de Cœlib.) asserts that God prefers eunuchs only before those who transgress the law. But he gives them a place better than his other sons, &c.! Protestants (Bible, 1603) understand that eunuchs shall be called after (or according to) God’s people, and be of the same religion, which implies no preference at all. They add, therefore, yea, under Christ the dignity of the faithful shall be greater than the Jews were at that time; as if the comparison were between God’s servants before and after Christ, and not between eunuchs and such as have children. How much better is it for us to follow the holy Fathers, who hence commend those who make a vow of perpetual chastity? They shall possess an excellent dignity among the angels. (St. Basil, virg.) — The rewards of continency are great, eximia. (St. Cyril of Alexandria, hic.) — “In the eternal mansion they are preferred before children.” (St. Gregory, past. iii. 29., &c.) (Worthington) — Such spiritual eunuchs, as St. John the evangelist, are meant. “He hath chosen what the Lord would, that he should offer more than was commanded….He who is an eunuch, and performs all that is prescribed, shall have….the best place, so that he shall be a tower, and occupy the rank of a priest, and instead of children of the flesh, shall have many spiritual children.” (St. Jerome) (Haydock) — The law excluded eunuchs from the Church, Deuteronomy xxiii. 1. But under the gospel, they may enter heaven, Matthew xix., and 1 Corinthians vii. 32., &c. Daniel (i. 3.) and his companions were eunuchs, yet in high estimation; and virtuous eunuchs are commended, Wisdom iii. 13. (Calmet) — Choose. Observing the commandments and counsels, like religious men. (Menochius) — Those who choose to do more than is commanded, will have a greater reward. (Worthington)”
Source
1871
A.D.
1875
A.D.
Keil & Delitzsch Lutheran
1861–1875
“"For thus saith Jehovah to the circumcised, Those who keep my Sabbaths, and decide for that in which I take pleasure, and take fast hold of my covenant; I give to them in my house and within my walls a memorial and a name better than sons and daughters: I give such a man an everlasting name, that shall not be cut off." The second condition after the sanctification of the Sabbath has reference to the regulation of life according to the revealed will of God; the third to fidelity with regard to the covenant of circumcision. יד also means a side, and hence a place (Deu 23:13); but in the passage before us, where ושׁם יד form a closely connected pair of words, to which וּמבּנות מבּנים is appended, it signifies the memorial, equivalent to מצּבת (2 Sam 18; 1:1-24:25; Sa1 15:12), as an index lifted up on high (Eze 21:24), which strikes the eye and arrests attention, pointing like a signpost to the person upon whom it is placed, like monumentum a monendo. They are assured that they will not be excluded from close fellowship with the church ("in my house and within my walls"), and also promised, as a superabundant compensation for the want of posterity, long life in the memory of future ages, by whom their long tried attachment to Jehovah and His people in circumstances of great temptation will not be forgotten.”
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.