Deuteronomy 22:11 forbids the wearing of a garment that contains different fabrics. This command contains a spiritual principle with a profound impact.
The context of the prohibition against mixing wool and linen teaches that God wants us to remain separate from the world, not being unequally yoked with any part.
These verses contain the principle that materials of differing character are not to be combined. But they do allow combinations that are within God's laws.
Paul never taught any Jew to forsake the Law of Moses, but he did warn against Pharisaical additions for the expressed purpose of attaining justification.