1 Corinthians 9:6-9

Are Barnabas and I the only ones who must work to earn our living? No soldier ever serves in the army and pays his own salary. No one ever plants a vineyard without eating some of the grapes. No person takes care of a flock without drinking some of the milk. I do not say this by human authority; God’s law also says the same thing. It is written in the law of Moses: “When an ox is working in the grain, do not cover its mouth to keep it from eating.” When God said this, was he thinking only about oxen? No.