Matthew Poole and continuators on Leviticus 19:19

19 Ye shall keep my statutes f. Thou shalt not let thy cattle gender with a diverse kind : thou shalt not sow thy field with mingled seed : neither shall a garment mingled of linen and woollen come upon thee.

This was prohibited, partly to restrain the curiosity and boldness of men, who might attempt to amend or change the works of God: Partly that by the restraints here laid even upon brute-creatures men might be taught to abhorre all unnatural and unlawful lusts: Partly to teach the Israelites to avoid mixtures with other Nations either in Marriage or in Religion: Which also may be signified by the following prohibitions.

See of this and the next Deut. 22. 9, 10, 11.