What is the meaning of "b'Vo'am"?
Radak: It is when Yisrael returned from the war.
Malbim: After defeating the Pelishtim, the army camp remained in Emek ha'Elah and fought their neighbors, and David became the head general. Then Sha'ul [and David] returned to his house in Giv'as Sha'ul.
Why does it say "b'Shuv David"?
Malbim: On the way to Sha'ul's house, David showed the head of Galyus in the cities they passed; he left in Yerushalayim (17:54).
What are "ha'Mecholos"?
Radak: They are instruments (in their hands).
Radak citing Targum Yonasan: To praise amidst dance.
Why did they come to greet only Sha'ul, and not David?
Malbim: One does not honor a slave in front of his master.
What are "Shalishim"?
Rashi citing Targum Yonasan: They are Tzeltzelin, an instrument (cymbals).
Radak: They are instruments with three strings.
