What is the meaning of "Ki Ya'atzti"?
Rashi: This is my counsel.
How was Chushai's counsel different?
Malbim: It is different in all four points (refer to 17:1:1:1). (a) They should not0 pursue immediately, rather, first gather all of Yisrael. (b) Do not go with a small number, rather, with all of Yisrael. (c) Achitofel should not pursue, rather, Avshalom should be with them. (d) They should not pursue at night, rather, during the day (refer to 17:12:2:2), and we will know clearly where David is.
What is the meaning of "u'Fanecha Holchim ba'Kerav"?
Rashi, Targum Yonasan: You will be at the head.
Radak: You will be in the war, unlike Achitofel's counsel that he will lead 12,000. Yisrael will be strengthened to fight when you will be in the war. This is like "Im Ein Panecha Holchim" (Shemos 33:15 - if You will not go Yourself, rather, send a Shali'ach). 'Going' is attributed to the face, for guarding and supervision are [based on the eyes and ears] in the face.
