Sforno on Exodus 9:32/ספורנו על שמות ט׳:ל״ב

1והחטה והכסמת, take note of the extent of the wickedness of Pharaoh and his servants. Even though the wheat and the spelt had not yet been destroyed, and Moses had prayed for the removal of the plague of hail, and Pharaoh had observed that all the destructive forces had ceased to be active as an immediate result of Moses’ prayer, something which made plain that but for Moses’ prayer the destruction would have continued, Pharaoh heaped more sins on top of the ones already committed, so as to make the ultimate retribution he would suffer even more terrible.