We mentioned yesterday the reason why Jeremiah refused the office of teaching, even because he thought himself unequal to the work; and for this reason he called himself a child, not in age, but in knowledge. Hence the word |child| is to be taken metaphorically; for thereby the Prophet confessed that he was not sufficiently qualified as to knowledge and practice. Some, as I have said, have unwisely applied this to his age. Though then he was of a mature age, yet he called himself a child, because of his unskillfulness, and because he possessed not the gifts necessary for an office so important.
Now follows the answer given to him, Say not, I am a child; for thou shalt go, etc. God not only predicts here what the Prophet was to do, but declares also what he designed him to do, and what he required from him, as though he had said, |It is thy duty to obey, because I have the right to command: thou must, therefore, go wheresoever I shall send thee, and thou must also proclaim whatsoever I shall command thee.| By these words God reminds him that he was his servant, and that there was no reason why a sense of his own weakness should make him afraid; for it ought to have been enough for him simply to obey his command.
And it is especially necessary to know this doctrine: for as we ought to undertake nothing without considering what our strength is, so when God enjoins anything, we ought, immediately to obey his word as it were with closed eyes. Prudence is justly praised by writers; and it is what ought to be attended to by all generally; they ought to consider what the shoulders can bear, and cannot bear. For whence is it that many have so much audacity and boldness, except that they hurry on through extreme self -- confidence? Hence, in all undertakings, this should be the first thing, that every one should weigh well his own strength, and take in hand what comports with the measure of his capacity. Then no one would foolishly obtrude himself, and arrogate to himself more than what is right. But when God calls us, we ought to obey, however deficient we may in all things be: and this is what we learn from what God says here, Say not, I am a child; that is, |though thou, indeed, thinkest thyself destitute of every qualification, though thou art conscious of thine own weakness, yet thou shalt go, thou must go wheresoever I shall send thee.| God, then, requires this honor to be simply conceded to him, that men should obey his commands, though the qualification necessary to execute them be wanting. It afterwards follows --