1 And in that day thou shalt say, Jehovah, I will praise thee; for though thou wast angry with me, thine anger is turned away, and thou hast comforted me.
Jerome · AD 420 And you shall say on that day: I will praise you, O Lord, for you were angry with me, but your anger has turned away, and you have comforted me. Behold, God is my salvation; I will trust, and will not be afraid; for the Lord God is my strength and my song, and he has become my salvation.
Thomas Aquinas · AD 1274 384. I will confess. Here the thanksgiving for the benefit they received is set out, which indeed the prophet already saw by the prophetic spirit and promised to the people.
2 Behold,God is my salvation: I will trust, and not be afraid; for Jah, Jehovah, is my strength and song, and he is become my salvation.
Bonaventure · AD 1257 This fortitude is from God redeeming through the incarnation of the divine Word. Whence Isaiah says: "The Lord is my strength and my praise, and he has become my salvation; you shall draw waters with joy from the fountains of the Savior." These are the waters in which the soul is strengthened, purified, redeemed, sanctified, and snatched from the power of demons.
Thomas Aquinas · AD 1274 386. Against the second evil, he confesses confidence in God: behold, God is my savior, freeing the people from the slavery of Babylon, or more truly, who will save his people: for he shall save his people from their sins (Matt 1:21); fear you not, my servant Jacob, says the Lord, neither be dismayed, O Israel: for behold, I will save you from a country afar off (Jer 30:10).
3 And with joy shall ye draw water out of the wells of salvation.
Ambrose of Milan · AD 397 Better is the foolishness that has eyes to see its own wounds than wisdom that does not have them. And therefore, with the gaze of his own foolishness, such a great king admits to being afflicted by miseries; so that he may find the remedy of repentance, which Judas, who possessed a field with the wages of iniquity, could not find.
Cassiodorus · AD 585 We say that God is … a fountain because he fills the thirsty and empty.
Thomas Aquinas · AD 1274 387. You shall draw. Here he promises the benefit: waters, of comfort, cooling them against the heat of tribulation. 391. It is to be noted on the words, you shall draw waters (Isa 12:3), that there is first, the water of doctrine, below: all you that thirst, come to the waters (Isa 55:1); second, of grace: he that believes in me, out of his belly shall flow rivers of living wa…
4 And in that day shall ye say, Give ye thanks to Jehovah, call upon his name, declare his deeds among the peoples, make mention that his name is exalted.
Jerome · AD 420 (Verses 4, 5.) And you shall say on that day, confess the Lord and invoke His name: make His inventions known among the peoples: remember, for His name is exalted. Sing to the Lord, for He has done great things: announce this in all the earth.
Thomas Aquinas · AD 1274 388. And you shall say. Here he foretells that the people shall also sing, after the benefit has been received, and it contains the mutual exhortation of the people to divine praise. Exhortation to three things is set out: to the confession of divine praise, to thanksgiving: sing to the Lord (Isa 12:5), to shared rejoicing: rejoice (Isa 12:6).
5 Sing psalms of Jehovah, for he hath done excellent things: this is known in all the earth.
Thomas Aquinas · AD 1274 389. Sing to the Lord. Here he exhorts them to thanksgiving; and first, that they give thanks to God: sing to the Lord, for he has done great things, in freeing us: sing to the Lord a new canticle: because he has done wonderful things (Ps 97[98]:1); second, that it be announced to the world: show this forth in all the earth: bless the God of heaven, give glory to him in the sig…
6 Cry out and shout, thou inhabitress of Zion; for great is the Holy One of Israel in the midst of thee.
Jerome · AD 420 (Verse 6) Rejoice and praise, O dwelling place of Zion, for the Holy One of Israel is great among you. First, it must be said according to the letter: O dwelling place of Zion, rejoice and praise your God, for He who was once considered your God and was enclosed within the narrow bounds of the land of Judaea, now fills the whole earth with His knowledge.
Thomas Aquinas · AD 1274 390. Rejoice. Here the exhortation to exultation is set out; and first, that there be joy in their hearts: rejoice; second, that there be songs of joy in their mouths, praise; third, the reason for both is set out, for great is he, below: it shall rejoice with joy and praise (Isa 35:2). 394.