1 Corinthians 9:13-18

Know ye not that they that minister about sacred things eat of the things of the temple, and they that wait upon the altar have their portion with the altar? Even so did the Lord ordain that they that proclaim the gospel should live of the gospel. But I have used none of these things: and I write not these things that it may be so done in my case; for it were good for me rather to die, than that any man should make my glorying void. For if I preach the gospel, I have nothing to glory of; for necessity is laid upon me; for woe is unto me, if I preach not the gospel. For if I do this of mine own will, I have a reward: but if not of mine own will, I have a stewardship intrusted to me. What then is my reward? That, when I preach the gospel, I may make the gospel without charge, so as not to use to the full my right in the gospel.