Albert Barnes Commentary 2 Samuel 5:1

"Then came all the tribes of Israel to David unto Hebron, and spake, saying, Behold, we are thy bone and thy flesh." — 2 Samuel 5:1 (ASV)

The chronicler adds some interesting details (compare 2 Samuel 12:23-40), describing how the various tribes from both sides of the Jordan came to Hebron to make David king and detailing the joyful festivities on that occasion.

The events that God's providence had been leading toward had now reached their consummation. Saul, Jonathan, Abner, and Ish-bosheth were dead; David was already the head of a large portion of Israel; and the Philistines, along with perhaps the remnant of the Canaanites, were restless and threatening.

It was therefore clearly in the Israelite nation's best interest to unite under the sovereignty of the valiant and virtuous son of Jesse—their former deliverer and the man designated by the word of God as their Captain and Shepherd. Accordingly, he was at once anointed king over all Israel (compare 2 Samuel 2:4 note).