R. Yossi Haglili says: "You shall eliminate leaven from your house" — before the eve of the festival. You say this, but perhaps (the meaning is) on the festival itself? "Ach" (i.e., "No labor shall be done in them ach ['only']" divides (the day into "permitted" [for the retention of chametz (i.e., until the sixth hour)] and "forbidden" [after the sixth hour]).