I Corinthians 9:11-14

If we have sown spiritual things for you, is it a great thing if we reap your material things? If others are partakers of this right over you, are we not even more? Nevertheless we have not used this right, but endure all things lest we hinder the gospel of Christ. Do you not know that those who minister the holy things eat of the things of the temple, and those who serve at the altar partake of the offerings of the altar? Even so the Lord has commanded that those who preach the gospel should live from the gospel.