Athanasius of Alexandria

Concerning Jeremiah, God says, "Before I formed you in the womb, I knew you." … If such terms are used in Scripture of things created, but the term ever is used of the Word, then it follows, O enemies of God, that the Son did not come out of nothing, nor is he to be numbered at all among created things, but he is the Father's image and eternal word, never having not existed, but never existing as the eternal radiance.

Discourses Against the Arians 1.4.13 ↗

Cyril of Jerusalem

He is not ashamed to assume flesh, who is the creator of those very parts. Who tells us this? The Lord said to Jeremiah: "Before I formed you in the belly, I knew you. Before you came forth out of the womb, I made you holy." If, then, in making humanity he was not ashamed of the contact, was he ashamed in making for his own sake the holy flesh, the veil of his Godhead? It is God who even now creates children in the womb, as it is written in Job, "Didn't you pour me out as milk and curdled me like cheese? …

Catechetical Lecture 12:26 ↗

Irenaeus

Now, that the Word of God forms us in the womb, He says to Jeremiah, "Before I formed thee in the womb, I knew thee; and before thou wentest forth from the belly, I sanctified thee, and appointed thee a prophet among the nations." And Paul, too, says in like manner, "But when it pleased God, who separated me from my mother's womb, that I might declare Him among the nations." As, therefore, we are by the Word formed in the womb, this very same Word formed the visual power in him who had been blind from his birth; showing openly who it …

Against Heresies 5:15.3 ↗

Ambrose of Milan

Just as the spiritual bosom of the Father is understood as a certain inner secret of paternal love and nature, in which the Son is always present, so also the spiritual bosom of the Father is the womb, the secret of the innermost mystery, from which the Son has proceeded as though from a generative womb. …

On the Blessings of the Patriarchs 11.51 ↗