2 Samuel 5:1-5 NKJV

1 Then all the tribes of Israel came to David at Hebron and spoke, saying, "Indeed we are your bone and your flesh.
2 Also, in time past, when Saul was king over us, you were the one who led Israel out and brought them in; and the Lord said to you, 'You shall shepherd My people Israel, and be ruler over Israel.' "
3 Therefore all the elders of Israel came to the king at Hebron, and King David made a covenant with them at Hebron before the Lord. And they anointed David king over Israel.
4 David was thirty years old when he began to reign, and he reigned forty years.
5 In Hebron he reigned over Judah seven years and six months, and in Jerusalem he reigned thirty-three years over all Israel and Judah.