Why did Sha'ul not need to announce [to gather men to chase David], like he did above (23:9)?
Malbim: They had already gathered for the war against Pelishtim. Above he did not pick 3,000 (rather, he took everyone), for he concealed his intent. He wanted them to think that he goes to fight Pelishtim.
What are "Tzurei ha'Y'elim"?
Rashi: They are rocks of the Ye'elim. Rashi (Devarim 14:5) - Ye'el is Ako, one of the Tahor Chayos - a wild goat, or ibex. Radak - its nature is to go on rocks - "Ya'alei Sela" (Iyov 39:1). It is a wild goat (Chulin 80a). 1
Targum Yonasan: They are Shekifei Cheifaya. Radak - I do not know why he translated Ye'elim as Cheifaya 2 .
Malbim (3): They are tall rocks in Midbar Ein Gedi. Ye'el's nature is to go on tall rocks - "Harim ha'Gevohim la'Y'elim" (Tehilim 104:18).
Chulin 80a does not mention Ye'el! It brought opinions that a forest goat is Ako, Te'o, Zemer (to Chayos listed in the verse), or a regular goat (a Behemah). (PF) The Aruch says that Ye'el is a female lamb. Tosfos (Rosh Hashanah 26b) rejected this, for the Targum of Ako is Yala.
Kli Yakar: The prefix Hei in ha'Y'elim forced him to translate so. They are tall rocks with cavities like a Kipa (dome) in which a person can hide. (Yonasan gave the same Targum for "Se'ifei ha'Sela'im"(Yeshayah 57:5); Rashi says that they are holes in rocks. Seemingly, Cheifaya is like Kipi, the Targum of Tzurei (rocks), and Shekifei is the Targum of Ye'elim! - PF) Ye'elim is an expression of Ha'alim (hiding) or Iluy (elevation).
