Komentaryo sa Exodo 8:11: Rashi, Rashbam, Kli Yakar & Sforno

והכבד את לבו HE ALLOWED HIS HEART TO BE HARDENED — The word הַכְבֵּד expresses doing something (the Hebrew infinitive but having a past meaning) just as, (Genesis 12:9) “going (הלוך) and journeying (ונסוע)”. So, too, (2 Kings 3:24) “and smiting (והכת) Moab”; (I Samuel 22:13) “and enquiring (ושאול) of God for him”; (1 Kings 20:37); “smiting (הכה) and wounding (ופצוע)”.

HE MADE IT HARD [HACHBED]. Because this plague was great, his mind did not strengthen by itself, rather, he affirmatively acted wrongly to harden his mind.

“And Pharaoh saw that there was relief.” This expression was not used in any plague except for the plague of frogs. This is because with all other plagues, when they departed, they departed completely with no trace remaining after their removal. Therefore, it’s not so surprising that Pharaoh returned to his stubbornness, as what has passed is gone. However, with the frogs, even after the plague was removed, it was not completely gone because they didn’t go away but rather died, and the land stank. Pharaoh should have been humbled at least because of the stench that remained from the frogs. Regarding this, the verse explains as if justifying: he saw that there was relief, and he hardened his heart because a bad smell is only harmful in a confined space, but in an open, spacious area, the smell doesn’t affect as much. Therefore, when Pharaoh saw that there was relief, that the land of Egypt was spacious and wide, and the bad smell would not harm him, he hardened his heart as before.

‎ כאשר דבר ה׳ AS THE LORD HAD SPOKEN — And where had He said this? When He said, (Exodus 7:4) “Pharaoh will not hearken to you”.