Deuteronomy 22:

  9 Thou shalt not sow thy vineyard with divers seeds: lest the fruit of thy seed which thou hast sown, and the fruit of thy vineyard, be defiled. 10 Thou shalt not plow with an ox and an ass together.

Luke 9:62 And Jesus said unto him, No man, having put his hand to the plough, and looking back, is fit for the kingdom of God.

1Corinthians 9:10 Or saith he it altogether for our sakes? For our sakes, no doubt, this is written: that he that ploweth should plow in hope; and that he that thresheth in hope should be partaker of his hope.