Why is the scoffer stricken?
Rashi (from Tanchuma 1 Yisro 3): This refers to the Makos against Pharaoh and the war with Amalek.
R. Yonah: Even though there is no hope for a Letz via rebuke or the staff, it is proper to afflict and hit him for transgressing Torah and deviating from the law, so those who hear will be chastised and fools will become wise - "veha'Nisharim Yishme'u v'Yira'u" (Devarim 19:20).
The Midrash mentions only Milchamas Amalek. (PF)
Which fool became wise?
Rashi (from Tanchuma Yisro 3): This refers to Yisro, who became wise and converted.
Malbim: A Pesi does not return to contemplate via rebuke of the Sechel, only via Musar and striking. If he sees that they strike a Letz, he will acquire Armah to understand that he should not go in the Letz' way.
What is the significance of "v'Hochi'ach l'Navon Yavin Da'as"?
R. Yonah: He will be careful not only about the matter for which he was rebuked. He will be careful also about other things due to what he was rebuked for. He will understand his deeds, search his ways and investigate when he sees that he stumbled in something else. He worries lest sin and stumbling will occur to him in other matters.
Malbim: A Navon does not need to see the Musar of the Letz. He understands Da'as via rebuke of the Sechel. He does not want to shame his parents; this suffices to deter him.
