Deuteronomy 22:9,10

Divers seeds Either, 1st, With divers kinds of seeds mixed and sowed together between the rows of vines in thy vineyard: which was forbidden to be done in the field, (Leviticus 19:19,) and here in the vineyard. Or, 2d, With any kind of seed differing from that of the vine, which would produce either herbs, or corn, or fruit-bearing trees, whose fruit might be mingled with the fruit of the vines. Now this and the following precepts, though in themselves small and trivial, are given, according to that time and state of the church, for instructions in greater matters, and particularly to commend to them simplicity in all their carriage toward God and men, and to forbid all mixture of their inventions with God's institutions in doctrine and worship. An ox and an ass Because the one was a clean beast, the other unclean; whereby God would teach men to avoid polluting themselves by the touch of unclean persons or things.