This is not (as heresy supposes) because Jeremiah existed before his
conception, but because the Lord, to whom things not yet made are already made,
foreknew that he was going to exist, as the apostle says: “he who calls things
that are not as though they were.” That he was sanctified in the womb we can
also understand according to this statement of the apostle: “He who set me
apart from the womb of my mother and called me through his grace was pleased to
reveal his son to me, in order that I might preach him among the Gentiles.”
John the Baptist was also sanctified in the womb. He received the Holy Spirit,
stirred in the womb and spoke through the mouth of his mother.
Furthermore, when he says, “I appointed you a prophet to the nations,”
he wishes this to be understood: later on in this very prophet, we are going to
read that he prophesied not only to Jerusalem but also to many of the
surrounding nations. Certain people understand this passage to be about the
Savior, who was in the strictest sense a prophet to the nations and who called
all nations through the apostles. For that one, before being formed in the
virgin’s womb and coming forth from his mother’s body, was truly sanctified in
the womb and known to the Father—indeed, he was always in the Father, and the
Father was always in him. (Jerome, Commentary on Jeremiah [trans.
Michael Graves; Ancient Christian Texts; Downers Grove, Ill. : IVP Academic,
2011], 3)
