What is the meaning of "Mah Li v'Lachem"?
Malbim: In any case, there is no need to stop him. (a) If he curses by himself (not due to Hashem), it will not harm me and you. (b) And if Hashem told him, one cannot ask why he does so!
What is the meaning of "Koh Yekalel"?
Rashi: Ken (so) he will curse.
Malbim: [If he curses by himself], let him curse as much as he wants. One who is disgraced through obvious falsity, this is not disgrace. Who doesn't know that David did not [order to] kill Avner or Ish Boshes, and did not take kingship from Beis Sha'ul by force?!
Did Hashem tell him to curse?
Rashi: It is not possible that a man like him, the head of a Sanhedrin, would curse the king, if not that he was told from Hashem.
Radak #1: It is as if Hashem told him, for He wanted me to need to go to and fro.
Radak #2: Hashem aroused his spirit to curse me, for a punishment for my sin.
