Why did the Navi omit the years that David ruled in Chevron over Yehudah, and Ish Boshes ruled over the rest of Yisrael?
Malbim: The author always wants to aggrandize David's level. He primarily teaches about David's kingship over the entire nation, for then Shmuel's Nevu'ah was fulfilled.
Why did they tell David "we are your bone and flesh"?
Radak and Malbim citing Mahari, both in Shmuel II, 5:1: Even though you are from Yehudah, also we are related to you ? we are all Bnei Yisrael.
Kol Eliyahu, Divrei Eliyahu (Bereishis 29:14): A baby's bones are due to his father; his flesh is due to his mother. You are our relatives regarding both of these 1 . I.e. also your maternal ancestor (Rus ha'Mo'aviyah) was from Kahal Hashem, unlike Do'eg's claim.
Kol Eliyahu, Divrei Eliyahu: Lavan said so to Yakov, for 'both your father (our grandfathers were brothers) and mother are related to me.'
