1 corn 9:15-18

15But I have not used any of these rights. And I am not writing this in the hope that you will do such things for me. I would rather die than have anyone deprive me of this boast. 16Yet when I preach the gospel, I cannot boast, for I am compelled to preach. Woe to me if I do not preach the gospel! 17If I preach voluntarily, I have a reward; if not voluntarily, I am simply discharging the trust committed to me. 18What then is my reward? Just this: that in preaching the gospel I may offer it free of charge, and so not make use of my rights in preaching it.