Nay but, O man, who art thou - As if he had said: Weak, ignorant man, darest thou retort on the infinitely good and righteous God? Reflect on thyself; and tell me, after thou hast abused the grace of God, and transgressed his laws, wilt thou cavil at his dispensations? God hath made, created, formed the Jewish nation; and shall the thing formed, when it hath corrupted itself, pretend to correct the wise and gracious Author of its being, and say, Why hast thou made me thus? Why hast thou constituted me in this manner? Thou hast done me wrong in giving me my being under such and such conditions.
Old John Goodwin's note on this passage is at least curious: "I scarce (says he) know any passage of the Scripture more frequently abused than this. When men, in the great questions of predestination and reprobation, bring forth any text of Scripture which they conceive makes for their notion, though the sense which they put upon it be ever so uncouth and dissonant from the true meaning of the Holy Ghost, yet, if any man contradict, they frequently fall upon him with - Nay but, O man; who art thou? As if St. Paul had left them his heirs and successors in the infallibility of his spirit! But when men shall call a solid answer to their groundless conceits about the meaning of the Scriptures, a replying against God, it savours more of the spirit who was seen falling like lightning from heaven, than of His, who saw him in this his fall."