BT Šab 124b(39) :איתווס מסאניה טינא‏ : his shoes were soiled with mud
See the entire entry for ˀws vb. D to soil, make dirty

BT Šab 124b(39) :הוה קא מכפר ליה בחספא‏ : he was wiping them off [i.e. his shoes] with a sherd
See the entire entry for kpr vb. to wipe off; to deny