1 Corinthians 9:10

"For it is written in the law of Moses, Thou shalt not muzzle the ox when he treadeth out the corn." And on what account hath he mentioned this, having the example of the priests? Wishing to establish it far beyond what the case required. Further, lest any should say, "And what have we to do with the saying about the oxen?" he works it out more exactly, saying, "Is it for the oxen that God careth;" Doth God then, tell me, take no care for oxen? Well, He doth take care of them, but not so as to make a law concerning such a thing as this. So that had he not been hinting at something important, training the Jews to mercy in the case of the brutes, and through these, discoursing with them of the teachers also; he would not have taken so much interest as even to make a law to forbid the muzzling of oxen. Wherein he points out another thing likewise, that the labor of teachers both is and ought to be great. And again another thing. What then is this? That whatever is said by the Old Testament respecting care for brutes, in its principal meaning bears on the instruction of human beings: as in fact do all the rest: the precepts, for example, concerning various garments; and those concerning vineyards and seeds and not making the ground bear divers crops, and those concerning leprosy; and, in a word, all the rest: for they being of a duller sort He was discoursing with them from these topics, advancing them by little and little. And see how in what follows he doth not even confirm it, as being clear and self-evident. For having said, "Is it for the oxen that God careth?" he added, "or saith he it altogether for our sake?" Not adding even the "altogether" at random, but that he might not leave the hearer any thing whatever to reply. And he dwells upon the metaphor, saying and declaring, "Yea for our sakes it was written, because he who ploweth ought to plow in hope;" i.e., the teacher ought to enjoy the returns of his labors; "and he that thresheth ought to thresh in hope of partaking." And observe his wisdom in that from the seed he transferred the matter to the threshing floor; herein also again manifesting the many toils of the teachers, that they in their own persons both plough and tread the floor. And of the ploughing, because there was nothing to reap, but labor only, he used the word, "hope;" but of treading the floor he presently allows the fruit, saying, "He that thresheth is a partaker of his hope." Further, lest any should say, "Is this then the return for so many toils," he adds, "in hope," i.e., "which is to come." No other thing therefore doth the mouth of this animal being unmuzzled declare than this; that the teachers who labor ought also to enjoy some return.