What is the meaning of "b'Chanfei La'agei Ma'og..."?
Rashi: For flattery of frivolity of eating and drinking. They flatter to request that he give to them to eat and drink.
Radak: Both "b'Chanfei" and "La'agei" are Samuch to Ma'og. This is like "Nahar Nachalei Devash v'Chem'ah" (Iyov 20:17), "u'Sfunei Temunei Chol" (Devarim 33:19). They are flatterers and mockers; they engage in idle matters. B'Chanfei is like Im (with) Chanfei. The same applies to "Becha Tzareinu Nenage'ach" (below, 44:6). These lowly people gather with flatterers and mockers; they scoff and gnash their teeth at me.
Radak, according to Menachem: They are people who indulge in pleasures.
Malbim: It is a group of mockers and scoffers who say words of ridicule.
What is "Ma'og"?
Rashi: It is an expression of eating, like "Im Yesh Li Ma'og" (Melachim I, 17:12) of Eliyahu.
Rashi citing Menachem: It is a small cake, like "Im Yesh Li Ma'og" of Eliyahu. Refer to 35:16:1:3.
Radak #1: It is idle talk. This is like 'uv'Leshon Agah' (Sanhedrin 101b)
Radak #2: Evil counsel or evil deeds are metaphorically called Ma'og - "Efrayim Hayah Ugah Bli Hafuchah" (Hoshe'a 7:8).
What is the meaning of "Charok Alai Shineino"?
Radak: He is happy. One gnashes his teeth when he sees vengeance from his enemies.
Malbim: They gnash their teeth at me amidst scorn.
