Priests and Kings

The religion of ancient Israel, like those of most ancient Near Eastern societies, centered on a Temple, served by a caste of priests, who sacrificed offerings to their god. Priests (Kohens) claimed descent from Aaron of the tribe of Levi, who was believed to have been appointed by God to care for the Tabernacle and perform the priestly rituals. During the First Temple Era the priests were limited to their work in the Temple; political power officially rested in the hands of a king who was believed to rule by divine right.
In ancient Israel, as in most societies at that time, the priesthood was closely tied with the monarchy. According to the Hebrew Bible, the first Israelite king was Saul, of the tribe of Benjamin, although the tribe of Judah anointed Saul's protegeé and son-in-law, David as their own king after Saul's and his son's death in the battle with the Philistines (1 Samuel 31:2-10; 2 Samuel 2:4). After David reigned over Judah seven years and six months, he became king of all the tribes of Israel (2 Samuel 5:1-5).
Although this kingdom fragmented after the death of David's son Solomon, the dominant narrative in the Hebrew Bible portrays the house of David as the legitimate royal lineage, chosen by God (II Sam 7:11-16). Psalms 2: 7 and 89: 26–27 refer to David as the son of God; most interpret the word "son" in these contexts metaphorically, in accordance with usual ancient Hebrew poetic style, to mean that God loved David and that there would be a descendant of David
who would be as a son to God, either spiritually, or in terms of love, or pleasing to God, rather than literally. Geza Vermes has argued that the term "son of God" was often used to refer to the monarch.Both the Temple and the Davidic Monarchy were destroyed by the Babylonians in 586 BCE, when most Jews were forced into exile.