Cyprian

But as often as water is named alone in the holy Scriptures, baptism is referred to, as we see intimated in Isaiah: "Remember not," says he, "the former things, and consider not the things of old. Behold, I will do a new thing.…" There God foretold by the prophet that among the nations, in places that previously had been dry, rivers should afterwards flow plenteously and should provide water for the elected people of God, that is, for those who were made children of God by the generation of baptism. …

Epistle LXII:8 ↗

Clement of Alexandria

The Word says, "Look, I am doing something new, which no eye has seen, no ear heard, no human heart felt." These are to be seen, heard and grasped by a new eye, a new hearing and a new heart when the Lord's disciples speak, listen and act in the Spirit.

The Stromata Book 2 ↗

Ambrose of Milan

But He, although He took on Him our flesh, although He was made man that He might redeem man, and recal him from death, still, as being God, came upon earth in an extraordinary way, that as He had said, 'Behold I make all things new,' so also He might be born of an immaculate virgin, and be believed to be, as it is written, 'God with us.' But from their perverse ways they are induced to say 'She was a virgin when she conceived, but not a virgin when she brought forth.' Could she then conceive as a virgin, and yet not be able to bring …

Letter 42, To Pope Siricius ↗

Thomas Aquinas

Because of the newness of these things: behold I do new things, unheard of: behold, I make all things new (Rev 21:5); and because of their determination: I will make a way, for those going to the feasts, in the wilderness, that is, the land of the Jews, which was formerly a desert; rivers, of consolation: he has turned a wilderness into pools of waters (Ps 107:35). …

Commentary on Isaiah ↗