1 Corinthians 9:13-15

Do you not know that those who perform sacred services eat the food of the temple, and those who attend regularly to the altar have their share from the altar? So also the Lord directed those who proclaim the gospel to get their living from the gospel. But I have used none of these things. And I am not writing these things so that it will be done so in my case; for it would be better for me to die than have any man make my boast an empty one.