What is the meaning of "Achishah Miflat"?
Radak: I will rush to save myself.
Malbim: Achitofel had counseled to chase after David that night and kill him in the Midbar. Chushai ha'Archi annulled his counsel, and said that David would not lodge the people with him [stationary. Rather, they are fleeing; you will not find them.] Meanwhile, he informed David. David decided not to lodge in the Midbar, and fled.
What is "[me'Ru'ach] So'ah [mi'Sa'ar]"?
Rashi (8): They are like Ru'ach Sa'arah (a storm wind) that uproots trees. This is like "va'Yasa ka'Etz" (Iyov 19:10).
Rashi (8, citing Menachem): This is [travel,] like "va'Yis'u Bnei Yisrael" (Shemos 12:37).
Radak #1: From the war of these enemies of mine (Malbim - Avshalom), who are like a storm wind. We do not find So'ah elsewhere in Tanach.
Radak #2: So'ah is like Nos'ah, but the Nun is omitted. This is like "v'Ru'ach Nasa me'Es Hashem" (Bamidbar 11:31).