Then said I, Ah, Lord GOD! behold, I cannot speak: for I am a child.
All Commentaries on Jeremiah 1:6 Go To Jeremiah 1
Jerome
AD 420
This statement from Paul: "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." (Gal 1:15-16) 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.
Ah, ah, ah, Lord God: He pleads against his office, which in view of his age he cannot fulfill, showing the same modesty as Moses, who said that he was slight and meager of voice. But Moses was summoned, as it were, at a great and robust age, whereas Jeremiah is given the grace of boyhood, which is adorned with modesty and reserve.