Why did Yonason strike Netziv Pelishtim?
Radak: It was in order to rebel against them.
Malbim (1,3) : It was without his father's knowledge. Hashem caused that Sha'ul need to fight, to punish him for not waiting like Shmuel commanded (10:8).
What is "Netziv Pelishtim"?
Rashi: It is an officer appointed over Yisrael. They stationed him in Giv'as Binyamin.
If Geva the same as Giv'as Binyamin?
Rashi (Shoftim 19:12). Yes.
Radak: No. They are different, and so it says in Yehoshua 1 .
I do not understand his proof. Geva is merely listed among Binyamin's cities, and it was later given to the Kohanim (Yehoshua 18:24, 21:17)! Giv'as Binyamin is not mentioned in the Sefer! Radak (15) says that Sha'ul went with Shmuel to Giv'as Binyamin, and the next verse says that he was in Geva, but perhaps he went there in between - refer to 13:15:1:2,3.
Did Sha'ul himself blow the Shofar in the entire land?
Radak: No, he did not leave Gilgal; he commanded others to blow. This is like "va'Yiven Shlomo Es ha'Bayis" (Melachim 1 6:14).
What did Sha'ul want Yisrael to hear?
Rashi: That we had rebelled against the Pelishtim, so people should guard themselves from them.
Radak, Malbim: They should go out to fight. Surely the Pelishtim will make war when they hear that their Netziv was killed!
