Why is "Ish" pronounced, but not read?
Radak: It refers to David. His counsel was proper for David like asking Devar Hashem. He was his counselor, like it says in Divrei ha'Yamim I, 27:33. It says "Ish", for his counsel was [proper for] anyone who asked. It says "l'David", for he used to counsel him constantly.
Radak citing Shochar Tov 3: [Regarding counsel] he was not [like] a man, rather, [like] an angel. Kli Yakar - what one asked him, was like the Kohen Gadol asking the Urim v'Tumim. He is not [like] a man, rather, [like] an angel - "Sifsei Chohen
Why does it say that his counsel was like one who asks Devar Hashem? This was a terrible counsel!
Kli Yakar: It was good for what Avshalom wanted. Before, people feared to support Avshalom, lest later he make Shalom with David, and David will resent those who supported Avshalom. Now, everyone would know that Avshalom hates David and will not make Shalom with him. Even though a Midrash says that Achitofel had evil intent (to kill Avshalom for raping the Pilagshim, and make himself king), the counsel was good for Avshalom.
Torah ha'Temimah: His counsel was so established, that people did not question his counsel, just like they do not question Devar Hashem.
Why does it say "Gam l'David Gam l'Avshalom"?
Radak: Each Gam includes the other, like "Gam Tzonchem Gam Bekarchem" (Shemos 12:32). Now he became advisor to Avshalom like he had been for David.
Kli Yakar: Just like his counsel with David was Emes and Tamim (pure truth), his counsel with Avshalom was purely against David.
Kli Yakar citing ha'Efod: He counseled both of them together. I.e. he already counseled Avshalom when he used to counsel David.
