Charles Ellicott Commentary Deuteronomy 22:9

"Thou shalt not sow thy vineyard with two kinds of seed, lest the whole fruit be forfeited, the seed which thou hast sown, and the increase of the vineyard." — Deuteronomy 22:9 (ASV)

Defiled —or sanctified. Different crops become “common” at different times. The year’s corn was freed by the wave-sheaf and wave-loaves. The trees not for five years.

The rule about the ox and the ass may rest partly on humane considerations, as the gait and pulling strength of the two creatures are so very different. St. Paul gives a spiritual sense to this precept in 2 Corinthians 6:14: Be not unequally yoked together with unbelievers. The ox was a clean animal and fit for sacrifice, while the ass was unclean and must be redeemed with a lamb. Thus, the clean and the unclean were not to till the holy land of Jehovah together.

All these precepts are part of the laws of holiness in Leviticus—rules of behavior arising from the fact that Israel is the special people of a holy God.