Albert Barnes Commentary Jeremiah 1:5

"Before I formed thee in the belly I knew thee, and before thou camest forth out of the womb I sanctified thee; I have appointed thee a prophet unto the nations." — Jeremiah 1:5 (ASV)

Rather, “Before I formed thee in the belly.” I approved of you (as one fit for the prophetic office), and “before thou camest forth from the womb” I made you holy (dedicated you to holy uses); I have appointed you (now by this public call to be) “a prophet unto the nations.”

Unto the nations — The privileges contained in this verse are so great as in their full sense to be true only of Christ Himself, while to Jeremiah they belong as he was in so many particulars a type of Christ.