"wherewith you cover yourself": to exclude a duster, which does not cover his head and most of his body.
(Devarim 22:13) "If a man take a wife, and he come upon her, and he hate her": R. Yehudah says: If he cohabits with her, he receives stripes (for libeling her [viz. Devarim 22:14]); if not, he does not receive stripes.