What does "Efrati" connote?
Rashi: Beis Lechem is in Eretz Efrat. (Also refer to 1:1:5:1, 3-5.)
Why does it say "ha'Zeh"?
Radak: Above it said that he played music for Sha'ul.
Here it says that he had eight sons. In Divrei ha'Yamim 1 2:15 it says that David (the youngest) was the seventh!
Rashi: One of them died afterwards, therefore he is omitted there.
What is the meaning of "Ba va'Anashim"?
Rashi: He was counted among gatherings of the important people.
Radak: He was old, and could not come and go [by himself to see his sons in the war]. Also "v'Avraham Zaken Ba va'Yamim" (Bereishis 24:1); he was old and weak, a sign of [being close to] death, so he needed to take a wife for his son in his own lifetime. There is a Patach under the Veis, even though we do not know which men it discusses.
Radak (from Brachos 58a) He was accompanied by a multitude (600,000) when he went in or out, and he would teach to a multitude. 1
Yevamos 76b: He entered and left with a multitude. Rashi - he was appointed over 600,000 men.
Why was David not at the war for the 40 days that Galyus blasphemed? He was a Gibor, and he was with Sha'ul and carried his weapons!
Radak: He was not always with Sha'ul; he would go [to Sha'ul] and return; he did not entirely abandon the flock (refer to 17:15:1:1). It sufficed for three of Yishai's eight sons to be at the war.
Malbim: The custom was that the older sons went to the war and the younger stayed home to serve their father, especially since Yishai was old and had property, and needed most of his sons to serve him and guard his flock.
Malbim (16:21): "Va'Yhi Lo Nosei Kelim" does not mean that David carried Sha'ul's weapons. Rather, David was so elevated that he had someone to carry his (David's) weapons.
