The interpretation timeline
Isaiah 48:20 Douay-Rheims

Come forth out of Babylon, flee ye from the Chaldeans, declare it with the voice of joy: make this to be heard, and speak it out even to the ends of the earth. Say: The Lord hath redeemed his servant Jacob.

A.D. 373 – 1875 6 witnesses

Patristic

before A.D. 750
373
A.D.
c. A.D. 296–373
“Now my beloved, our will ought to keep pace with the grace of God and not fall short; lest while our will remains idle, the grace given us should begin to depart, and the enemy finding us empty and naked, … as was the case with him spoken of in the Gospel, from whom the devil went out. … For the departure from virtue gives place for the entrance of the unclean spirit.”
Source
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“"Come forth out of Babylon." If we take the command of the prophet in a spiritual sense, it means that we should fly from the city of this world, from the fellowship of wicked angels and wicked [people], with the feet of that faith that works through love, and we should press onward unceasingly toward the living God.”

Scholastic

c. 1100 – 1500
1167
A.D.
Ibn Ezra Jewish
1089–1167
“Go ye forth, etc. Now the prophet addresses those in exile. Utter it, etc. Make it known publicly; not alone that He will redeem His people, He will do wonders to them at their return to Zion. ולא צמאו That they will not thirst in the deserts, through which God will lead them.”
1256
A.D.
Thomas Aquinas Catholic
1225–1274
“Hear this, O house of Jacob, etc. Here he promises the liberation of the people. And it is divided into two parts. In the first he promises the liberation; in the second he carries out the order of the liberation, below, chapter 49: Hear, O islands, etc. The first is divided into two. In the first he arouses attention, calling to mind three things in which they gloried: namely, the dignity of their lineage, because they were from holy fathers: "of the waters," that is, of the seed. Against which, Matthew 3: "Do not think to say," etc.; the privilege of the knowledge of God: "who swear" — calling upon his name — "and remember" — as to the knowledge of him — "in truth," of heart, "nor in justice," of work. Above, chapter 29: "This people, with their lips, me," etc.; the worship of sacred religion: "from the city" — namely Jerusalem, in which was the worship of sacrifices — "they are called" — men of Jerusalem — 2 Maccabees 5: "not for the sake of the place, the nation," etc. Secondly he promises the liberation: "the former things, from that time," and concerning this he does three things. First he shows the majesty of God who promises; secondly, the prosperity of Cyrus who carries it out: "Assemble yourselves, all of you," etc.; thirdly he promises the liberation: "Come near to me," etc. Concerning the first, two things. First he shows the majesty of God from the foretelling of future things; secondly from the creation of things: "Hearken to me, Jacob," etc. Concerning the first, three things. First he assigns the reason for the foretelling of certain future things, setting down the foretelling itself: "the former things" — namely those which have already passed — "from that time," when they were still future, "suddenly," as regards others to whom they were not foretold. Ecclesiasticus 42: "declaring the things that have passed," etc.; setting down also the reason for this, which is taken from their condition — which he first states, "for I knew," from eternity. "That thou art hard" — hard to come to one's senses from evils; "thy neck" — that is, the stiffness of one's own judgment; "a sinew of iron," which cannot be bent; "thy forehead" — on account of shamelessness. Acts 5: "stiff-necked," etc.; Deuteronomy 31: "I know the contention," etc.; Jeremiah 3: "the forehead of a harlot," etc.; and then from this he draws out the reason, "I foretold," etc., as if to say: because thou wert prone to idolatry, I foretold it to thee, lest thou shouldst ascribe my benefits to idols. Hosea 2: "I will go after lovers," etc.; setting down also the manifestation of the things foretold: "which thou hast heard" — foretold to thee by me — "behold," fulfilled. Psalm 47: "As we have heard, so have we seen," etc. Secondly he assigns the reason for the concealment of certain future things, setting down first the concealment itself. As has been said, certain future things I foretold to thee; but certain future things have been kept in my foreknowledge, which thou dost not know, because I have not revealed them to thee. "Now" — that is, in time — "they are created," that is, brought forth in effect, and not from that time when I foreknew them; and "before the day" of their fulfillment, "thou hast not heard" of them, neither from me nor from the idols. 4 Kings 4: "the Lord hath hid it from me," etc. He also assigns the reason for this: "lest perhaps," as if to say: I did not reveal it for this reason, that thou mightest perceive thy own defect, and that of thy gods, in that thou canst not foreknow future things except those which I reveal to thee. "I have known" — by my own effort — "nor hast thou heard" — from the idols — the things opened by me. Psalm 63: "Man shall come to a deep heart," etc. He also sets down their condition, from which the aforesaid reason is drawn: "for I know." "From the womb" — that is, from the time when I carried thee through the desert as in a womb. Exodus 32: "I see that this people," etc.; above, chapter 24: "by the transgression of the transgressors," etc. Thirdly he excludes a certain objection: "for my name's sake." For someone could ask: since they are so hard, why then dost thou promise them good things, and hast done so? And to this objection he first sets down the response, recalling three benefits shown to them: "for my name's sake" — not on account of thy merit — "I will put far off," or have put far off, freeing them from punishments. Ezekiel 36: "Not for your sakes will I do this," etc., and "for my praise" — that is, I bound thee to my ceremonies and my praises, lest, offering sacrifices to idols, thou shouldst perish. Psalm 31: "with bit and bridle," etc. "I have refined," wishing to purge thee through tribulations, "but not as silver," which is purged. But thou hast not been corrected. Jeremiah 6: "in vain hath he melted," etc. "I have chosen," purging thee, namely, through poverty, punishing thee by the spoiling of goods. Gregory: "those whom the infirmity of their conduct wounds, the medicine of poverty heals." And this by correcting as a father. Secondly he sets down the exposition of the response: "for my own sake" — that I not be blasphemed, as though powerless to save the people whom I have chosen for myself; and "my glory" — namely, that the idols be judged stronger than I. Above, chapter 42: "my glory," etc. Hearken to me. Here he shows the divine majesty from the creation of things. "I will call," imposing upon each thing its proper work: "they shall stand," ready to obey. Above, chapter 40: "who hath weighed with three fingers," etc. Assemble yourselves, etc. Here he foretells the prosperity of Cyrus himself; and first he shows the concealment of this deed from others: "who among them?" — namely, among the idols — as if to say: none. Above, chapter 41: "who hath declared from the beginning," etc. Secondly he himself foretells his prosperity: "the Lord hath loved him" — namely Cyrus — advancing him into the kingdom; "in Babylon," capturing it; "his arm" — that is, by his own power slaying them. 1 Kings 27: "and indeed doing," etc. Thirdly he assigns the reason for his prosperity from divine aid: "I, I," etc.; "directed," not absolutely, but to this end, that he might destroy Babylon; otherwise it could not be expounded of Cyrus, but only of Christ, as Jerome says, because he was an idolater. Psalm 106: "he led them into the way," etc. Come near to me, etc. Here he promises liberation; and concerning this he does three things. First he arouses attention, setting down the divine authority: "in secret" — yet all the people saw the voices: Exodus 20. "From the beginning" — of the law given. "From the time," past, before they came to pass — the things which I foretell — "there I was," present to those future things, remaining, through the same "now" of eternity, throughout the whole succession of time. Or in the person of the Son, "there I was" — namely, in the Father according to his divinity — Proverbs 8: "when he weighed the foundations," etc.; setting down the truth of the prophet — who was sent by God — "and now, me": Isaiah, or me, Christ made man; "God," the Father; whence the three Persons are designated. Below, chapter 61: "the spirit of the Lord is upon me," etc. Secondly, there, "thus saith the Lord," he sets down the reason for the captivity, showing on God's part the help that was prepared. "Teaching" — against ignorance — and "governing in the way," of works, against weakness in acting. Psalm 31: "I will give thee understanding, and I will instruct," etc.; showing also the harm arising from the fault of the Jews. "O that thou hadst hearkened" — keeping them — "as an abundant river," "as the waves." The same, Psalm 80: "if my people had heard," etc. Thirdly, there, "go forth," he foretells the liberation; and concerning this he does three things. First he announces to them the departure from captivity, as certain of the liberation as if it were already present. "Go ye forth," etc.; Apocalypse 18: "go out from her," etc.; and he charges them to announce the benefit of God. "Declare ye," etc.; Jeremiah 50: "the voice of them that flee, and of them that have escaped," etc. Secondly he designates the benefit of consolation bestowed on those freed: "they thirsted not" — that is, the Lord will provide for them in all things just as when they went out from Egypt. Psalm 77: "he struck the rock, and they flowed," etc.; Numbers 21. Thirdly he takes away from the wicked the solace of peace: "there is no peace," below, chapter 57; 4 Kings 9: "what hast thou to do with peace," etc. (Collations, chapter 48) Poverty confers: the recognition of sins: "if they shall be bound," etc.; the preservation of virtues, Ecclesiasticus 10: "the poor man glorieth," etc.; quiet of heart, Tobit 5: "it was enough for us," etc.; the fulfillment of desire, Psalm: "the desire of the poor," etc.; participation in the divine sweetness, Psalm: "thou hast prepared in sweetness," etc.; exaltation, 1 Kings 2: "raising up from the dust," etc.; the heavenly inheritance, Matthew 5: "blessed are the poor," etc. The words of God are useful: for the illumination of the understanding, Proverbs 6: "the commandment is a lamp," etc.; for the delight of the affections, Psalm: "how sweet to the jaws," etc.; for the kindling of love, Jeremiah 20: "it came to be in the heart," etc.; Psalm: "the word of the Lord"; for the rightness of work, Psalm: "direct me in truth," etc.; for the attainment of glory, Proverbs 3: "keep the law"; for the instruction of others, 2 Timothy 3: "all doctrine divinely," etc.”

Post-Reformation

c. 1650 – 1900
1871
A.D.
1871
“Go . . . forth . . . end of the earth--Primarily, a prophecy of their joyful deliverance from Babylon, and a direction that they should leave it when God opened the way. But the publication of it "to the ends of the earth" shows it has a more world-wide scope antitypically; Rev 18:4 shows that the mystical Babylon is ultimately meant. redeemed . . . Jacob-- (Isa 43:1; Isa 44:22-23).”
Source
1875
A.D.
Keil & Delitzsch Lutheran
1861–1875
“So far the address is hortatory. In the face of the approaching redemption, it demands fidelity and faith. But in the certainty that such a faithful and believing people will not be wanting within the outer Israel, the prophecy of redemption clothes itself in the form of a summons. "Go out of Babel, flee from Chaldaea with voice of shouting: declare ye, preach ye this, carry it out to the end of the earth! Say ye, Jehovah hath redeemed Jacob His servant. And they thirsted not: He led them through dry places; He caused water to trickle out of rocks for them; He split rocks, and waters gushed out. There is no peace, saith Jehovah, for the wicked." They are to go out of Babylon, and with speed and joy to leave the land of slavery and idolatry far behind. Bârach does not mean literally to flee in this instance, but to depart with all the rapidity of flight (compare Exo 14:5). And what Jehovah has done to them, is to be published by them over the whole earth; the redemption experienced by Israel is to become a gospel to all mankind. The tidings which are to be sent forth (הוצי) as in Isa 42:1), extend from גאל to the second מים, which is repeated palindromically. Jehovah has redeemed the nation that He chose to be the bearer of His salvation, amidst displays of love, in which the miracles of the Egyptian redemption have been renewed. This is what Israel has to experience, and to preach, so far as it has remained true to its God. But there is no peace, saith Jehovah, to the reshâ‛ı̄m: this is the name given to loose men (for the primary meaning of the verbal root is laxity and looseness), i.e., to those whose inward moral nature is loosened, without firm hold, and therefore in a state of chaotic confusion, because they are without God. The reference is to the godless in Israel. The words express the same thought negatively which is expressed positively in Gal 6:16, "Peace upon the Israel of God." "Shâlōm is the significant and comprehensive name given to the coming salvation. From this the godless exclude themselves; they have no part in the future inheritance; the sabbatical rest reserved for the people of God does not belong to them. With this divine utterance, which pierces the conscience like the point of an arrow, this ninth prophecy is brought to a close; and not that only, but also the trilogy concerning "Babel" in chapters 46-49, and the whole of the first third of these 3 x 9 addresses to the exiles. From this time forth the name Kōresh (Cyrus), and also the name Babel, never occur again; the relation of the people of Jehovah to heathenism, and the redemption from Babylon, so far as it was foretold and accomplished by Jehovah, not only proving His sole deity, but leading to the overthrow of the idols and the destruction of their worshippers. This theme is now exhausted, and comes into the foreground no more. The expression איּים שׁמעוּ, in its connection with עמּי נחמוּ, points at once to the diversity in character of the second section, which commences here.”
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.