Before I formed thee in the belly I knew thee,.... Not merely by his omniscience, so he knows all men before their conception and birth; but with such a knowledge as had special love and affection joined with it; in which sense the Lord knows them that are his, as he does not others, and predestinates them unto eternal life; and which is not only before their formation in the womb, but before the foundation of the world, even from all eternity.
The forming of the human foetus is God's act, and a curious piece of workmanship it is; see Ps 139:15.And before thou camest forth out of the womb I sanctified thee; not by infusing holiness into him, but by separating him in his eternal purposes and decrees to the office of a prophet before he was born, and even before the world began; just as the Apostle Paul was separated to the Gospel of God, Ro 1:1, for it follows,and I ordained thee a prophet unto the nations; not to the Israelites only, who Jarchi thinks are so called, because they now followed the usages and customs of the nations; but to the Gentiles, against whom be was sent to prophesy, Jer 46:1 as Egyptians, Philistines, Moabites, Ammonites, and Chaldeans.