1 Corinthians 9:14

God's will is the same under the New Testament that it was under the Old; it is not as to the people a matter of liberty, so as men may choose whether they will maintain their ministers or not, there is an ordinance of God in the case: it is the will of God, that those who are taken off from worldly employments, and spend their time in the study and preaching of the gospel, should have a livelihood from their labour.