Charles Ellicott Commentary 1 Chronicles 11:3

"So all the elders of Israel came to the king to Hebron; and David made a covenant with them in Hebron before Jehovah; and they anointed David king over Israel, according to the word of Jehovah by Samuel." — 1 Chronicles 11:3 (ASV)

Therefore came all the elders of Israel. —The assembly of elders, the Senate of Israel, make a contract with David concerning his prerogative and the rights of his people, thus formally determining the manner of the kingdom. (Compare to 1 Samuel 8:9; 1 Samuel 8:9 and following, and 1 Samuel 10:25.) Representative institutions appear to have been the rule in the best period of Israel’s national existence. The elders or hereditary heads of the tribal subdivisions met in council to discuss and settle matters of national concern. (Compare to 1 Chronicles 12:23.)

Before the Lord. —In the presence of the high priest, and perhaps before the ark; compare Exodus 21:6 and 1 Samuel 2:25, where the priestly judge is called God, as representing the authority of the Divine judge (Exodus 22:28).

According to the word of the Lord by Samuel. —A reflection added by the chronicler, and based upon the facts related in 1 Samuel 15:28 and 1 Samuel 16:1–13.