After having spoken of his call, the Prophet adds, that he at first refused his office, and he states this for two reasons; first, that he might clear himself from every suspicion of rashness, for we know how much ambition prevails among men, according to what James intimates, that many wish to be teachers, (James 3:1) and there is hardly one who is not anxious to be listened to. Since, then, most men too readily assume the office of teaching, and many boldly intrude into it, Jeremiah, in order to avoid the very suspicion of rashness, informs us that he was constrained to take the office. Secondly, he says that he refused the office, that he might gain more esteem, and render his disciples more attentive. But why did he refuse to obey God, when called to the prophetic function? Because its difficulty frightened him: and yet this very reason ought to rouse readers to a greater attention, as it no doubt awakened hearers when Jeremiah spoke to them. If any one asks, whether Jeremiah acted rightly in refusing what God enjoined? the answer is, that God pardoned his servant, for it was not his design to reject his call, or to exempt himself from obedience, or to shake off the yoke, because he regarded his own leisure, or his own fame, or any similar considerations: Jeremiah looked on nothing of this kind; but when he thought of himself, he felt, that he was wholly unequal to undertake an office so arduous. Hence the excuse that is added is that of modesty. We then see that God forgave his timidity, for it proceeded, as we have just said, from a right feeling; and we know that from good principles vices often arise. But it was yet a laudable thing in Jeremiah, that he thought himself not sufficiently qualified to undertake the prophetic office, and that he wished to be excused, and that another should be chosen endued with more courage and with better qualifications. I shall proceed with what remains tomorrow.

There is no resistance on Jeremiah's part, but he shrinks back alarmed.
I cannot speak - i. e., "I cannot prophesy," I have not those powers of oratory necessary for success. The prophets of Israel were the national preachers in religious matters, and their orators in political.
I am a child - This implies nothing very definite about Jeremiah's age. Still the long duration of his prophetic mission makes it probable that he was very young when called to the office, as also were Isaiah, Hosea, Zechariah, and others.

I cannot speak - Being very young, and wholly inexperienced, I am utterly incapable of conceiving aright, or of clothing these Divine subjects in suitable language. Those who are really called of God to the sacred ministry are such as have been brought to a deep acquaintance with themselves, feel their own ignorance, and know their own weakness. They know also the awful responsibility that attaches to the work; and nothing but the authority of God can induce such to undertake it. They whom God never called run, because of worldly honor and emolument: the others hear the call with fear and trembling, and can go only in the strength of Jehovah.
"How ready is the man to go,
Whom God hath never sent!
How timorous, diffident, and slow,
God's chosen instrument!"

Then said I, (i) Ah, Lord GOD! behold, I cannot speak: for I [am] a child.
(i) Considering the great judgments of God which according to his threatening would come on the world, he was moved with a certain compassion on the one hand to pity them that would thus perish, and on the other hand by the infirmity of man's nature, knowing how hard a thing it was to enterprise such a charge, as in (Isaiah 6:11; Exodus 3:21, Exodus 4:1).

Then said I, Ah, Lord God!.... The word "Ah", or "Ahah", is used in distress and grief, as Kimchi observes; and is expressive of mourning and complaint, as Jarchi notes; and shows that the prophet was troubled and uneasy at his call, and would gladly have been excused on the following account:
behold, I cannot speak; or, "I know not how to speak" (r); properly and pertinently, politely and eloquently, especially before great personages, kings and princes, and the citizens of Jerusalem, being brought up in a rustic manner in the country. A like excuse Moses made, Exodus 4:10. The Targum is, "I know not to prophesy: for I am a child"; meaning either in knowledge and understanding, or in years; not a mere child, but a "junior", as the Septuagint version renders the word; or a "young man", as the Arabic version; so Samuel and Zechariah were young men, when they first ministered in their office, 1-Samuel 3:1. Abarbinel supposes that Jeremiah was now twelve or fifteen years of age; but it should seem rather that he was more, perhaps twenty years of age; since he seems to have prophesied to the men of Anathoth before he was sent to Jerusalem, Jeremiah 11:21.
(r) "uescio loqui", V. L. Munster, Vatablus, Junius & Tremellius; "non novi loqui", Pagninus, Montanus.

From the long duration of his office (Jeremiah 1:2-3; Jeremiah 40:1, &c.; Jeremiah 43:8, &c.), it is supposed that he was at the time of his call under twenty-five years of age.
child--the same word is translated, "young man" (2-Samuel 18:5). The reluctance often shown by inspired ministers of God (Exodus 4:10; Exodus 6:12, Exodus 6:30; Jonah 1:3) to accept the call, shows that they did not assume the office under the impulse of self-deceiving fanaticism, as false prophets often did.

The divine call throws Jeremiah into terror. Knowing well his too great weakness for such an office, he exclaims: Ah, Lord Jahveh! I know not how to speak; for I am נער, i.e., young and inexperienced; cf. 1-Kings 3:7. This excuse shows that לא יד means something else than לא אישׁ דברים, by which Moses sought to repel God's summons. Moses was not ready of speech, he lacked the gift of utterance; Jeremiah, on the other hand, only thinks himself not yet equal to the task by reason of his youth and want of experience.