1 Corinthians 9:17

(17) For if I do this thing willingly, I have a reward.—The previous words, “Yea, woe is unto me if I preach not the gospel,” are a parenthesis; and now the writer proves the truth of his assertion—that the necessity of preaching the gospel deprives the mere act itself of any grounds of boasting—by showing that if there were no necessity there would be a ground of boasting. The argument is this:—Suppose it to be otherwise, and that there is no such necessity, then, by voluntarily undertaking it, I have a reward. The undertaking it of my own free will would entitle me to a reward. But if (as is the case) not of my free will, but of necessity, then I am merely a steward—a slave doing his duty (1 Corinthians 4:1; Luke 17:7-10).

A dispensation of the gospel is committed unto me.—Better, I am entrusted with a stewardship.