1 Corinthians 9:15

9:15 But I have not used any of these rights. And I am not writing these things so that something will be done for me. In fact, it would be better for me to die than – no one will deprive me of my reason for boasting!

1 Corinthians 9:18

9:18 What then is my reward? That when I preach the gospel I may offer the gospel free of charge, and so not make full use of my rights in the gospel.