What more open than this? what more clear? I fear lest haply, while I discourse wishing to expound this, that become obscure which in itself is bright and clear. For they who understand not these words, or feign not to understand, do much less understand mine, or profess to understand: unless perchance they do therefore quickly understand ours, because it is allowed them to deride them being understood; but concerning the Apostle's words this same is not allowed. For this reason, where they cannot interpret them otherwise according to their own sentence, be it ever so clear and manifest, they answer that it is obscure and uncertain because wrong and perverse they dare not call it. Cries the man of God, "The Lord hath ordained for them which preach the Gospel, of this Gospel to live; but I have used none of these things;" and flesh and blood essayeth to make crooked what is straight; what open, to shut; what serene, to cloud over. "It was," saith it, "spiritual work that he was doing, and thereof did he live." If it be so, of the Gospel did he live: why then doth he say, "The Lord hath ordained for them which preach the Gospel, of the Gospel to live; but I have used none of these things?" Or if this very word, "to live" which is here used, they will needs also interpret in respect of spiritual life, then had the Apostle no hope towards God, in that he did not live by the Gospel, because he hath said, "I have used none of these things." Wherefore, that he should have certain hope of life eternal the Apostle did of the Gospel in any wise spiritually live. What therefore he saith, "But I have used none of these things," doth without doubt make to be understood of this life which is in the flesh, that which he hath said of the Lord's ordaining to them which preach the Gospel, that of the Gospel they should live; that is, this life which hath need of food and clothing, they by the Gospel shall sustain; as above he said of his fellow-apostles; of whom the Lord Himself saith, "The workman is worthy of his meat;" and, "The workman is worthy of his hire." This meat, then, and this hire of the sustenance of this life, due to evangelists, this of them to whom he evangelized the Apostle accepted not, saying a true thing, "I have used none of these things."
 1 Cor. ix.13-15 c11. And he goes on, and adjoins, lest perchance any should imagine that he only therefore received not, because they had not given: "But I have not written these things that they may be so done unto me: good is it for me rather to die than that any make void my glory."  What glory, unless that which he wished to have with God, while in Christ suffering with the weak? As he is presently about to say most openly; "For if I shall have preached the Gospel, there is not to me any glory: for necessity is laid upon me;"  that is, of sustaining this life. "For woe will be to me," he saith, "if I preach not the Gospel:" that is, to my own will shall I forbear to preach the Gospel, because I shall be tormented with hunger, and shall not have whereof to live. For he goes on, and says; "For if willingly I do this, I have a reward." By his doing it willingly, he means, if he do it uncompelled by any necessity of supporting this present life; and for this he hath reward, to wit, with God, of glory everlasting. "But if unwilling," saith he, "a dispensation is entrusted unto me:"  that is, if being unwilling, I am by necessity of passing through this present life, compelled to preach the Gospel, "a dispensation is entrusted unto me;" to wit, that by my dispensation as a steward, because Christ, because the truth, is that which I preach, howsoever because of occasion, howsoever seeking mine own, howsoever by necessity of earthly emolument compelled so to do, other men do profit, but I have not that glorious and everlasting reward with God. "What then," saith he, "shall be my reward?" He saith it as asking a question: therefore the pronunciation must be suspended, until he give the answer. Which the more easily to understand, let, as it were, us put the question to him, "What, then, will be thy reward, O Apostle, when that earthly reward due to good evangelists, not for its sake evangelizing, but yet taking it as the consequence and offered to them by the Lord's appointment, thou acceptest not? What shall be thy reward then?" See what he replies: "That, preaching the Gospel, I may make the Gospel of Christ without charge;" that is, that the Gospel may not be to believers expensive, lest they account that for this end is the Gospel to be preached to them, that its preachers should seem as it were to sell it. And yet he comes back again and again, that he may show what, by warrant of the Lord, he hath a right unto, yet doeth not: "that I abuse not," saith he, "my power in the Gospel." 
 1 Cor. ix.17
 1 Cor. ix.18