From the same as 'epher (in the sense of covering); a turban -- ashes.
see HEBREW 'epher
H666. apher
אֲפֵר noun [masculine] covering, bandage (Assyrian ipru, covering ZimBP 95, êpartu, garment, Id.ib. & DlPr 54) ׳א עַלעֵֿינָיו 1 Kings 20:38 compare 20:41.
אֶפְרֹחַ see פרח.