The interpretation timeline
Isaiah 56:6 Douay-Rheims

And the children of the stranger that adhere to the Lord, to worship him, and to love his name, to be his servants: every one that keepeth the sabbath from profaning it, and that holdeth fast my covenant:

1167 – 1875 5 witnesses

Scholastic

c. 1100 – 1500
1167
A.D.
Ibn Ezra Jewish
1089–1167
“Also the sons of the stranger, etc. The eunuchs are mentioned before the sons of the strangers, because they are the last named (ver. 3). Comp. And I gave to Isaac, Jacob, and Esau, and I gave to Esau, etc. (Jos. 24:4). To serve him. The service of the Lord consists in keeping His commandments.”
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
“Also the sons of the stranger that join themselves to the Lord,.... Having answered the objection and removed the discouragement of the eunuch, he now returns to the sons of the stranger, who also join themselves to the Lord, as the eunuch had done; see Isa 56:4 and who do this, to serve him, and to love the name of the Lord, to be his servants; who give up themselves to him, not only to be saved by him, but to serve him in righteousness and holiness, with reverence and godly fear, and from a principle of love to him; being heartily desirous, and accounting it an honour, to be his servants: everyone that keepeth the sabbath from polluting it, and taketh hold of my covenant; See Gill on Isa 56:4.”
Source
1871
A.D.
1875
A.D.
Keil & Delitzsch Lutheran
1861–1875
“The fears of proselytes from among the heathen are also removed. "And the foreigners, who have joined themselves to Jehovah, to serve Him, and to love the name of Jehovah, to be His servants, whoever keepeth the Sabbath from desecrating it, and those who hold fast to my covenant, I bring them to my holy mountain, and make them joyful in my house of prayer; their whole-offerings and their slain-offerings are well-pleasing upon mine altar: for my house, a house of prayer shall it be called for all nations." The proselytes, who have attached themselves to Jehovah (על־הא), (Note: The oriental reading, not in Isa 56:3, but here in Isa 56:6, is על־ה; the western, אל־ה. The Masora follows the western (מערבאי( nre), i.e., the Palestinian, and reckons this passage as one of the 31 על־ה in the Old Testament Scriptures.) the God of Israel, with the pure intention of serving Him with love, are not to be left behind in the strange land. Jehovah will bring them along with His people to the holy mountain, upon which His temple rises once more; there will He cause them to rejoice, and all that they place upon His altar will find a most gracious acceptance. It is impossible that the prophet should be thinking here of the worship of the future without sacrifice, although in Isa 53:1-12 he predicts the self-sacrifice of the "Servant of Jehovah," which puts an end to all animals sacrifices. But here the temple is called "the house of prayer," from the prayer which is the soul of all worship. It will be called a house of prayer for all nations; and therefore its nature will correspond to its name. This ultimate intention is already indicated in Solomon's dedicatory prayer (Kg1 8:41-43); but our prophet was the first to give it this definite universal expression. Throughout this passage the spirit of the law is striving to liberate itself from its bondage. Nor is there anything to surprise us in the breaking down of the party wall, built up so absolutely between the eunuchs on the one hand and the congregation on the other, or the one partially erected between the heathen and the congregation of Israel; as we may see from Isa 66:21, where it is affirmed that Jehovah will even take priests and Levites out of the midst of the heathen whom Israel will bring back with it into its own land.”
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.