1 Corinthians 9:7-9 New King James Version (NKJV)
7 Who ever goes to war at his own expense? Who plants a vineyard and does not eat of its fruit? Or who tends a flock and does not drink of the milk of the flock?
8 Do I say these things as a mere man? Or does not the law say the same also? 9 For it is written in the law of Moses, “You shall not muzzle an ox while it treads out the grain.” Is it oxen God is concerned about?