Solomon's annual offerings 9:25

The king offered sacrifices of worship three times annually, probably at the required feasts of Unleavened Bread, Pentecost (also called Harvest or Weeks), and Tabernacles (also called Booths or Ingathering).

"Solomon officiates at the three major festivals because in ancient Israel the king was a religious as well as a political leader. The king was God's son by adoption (Ps. 2:7), a priest after the order of Melchizedek (Ps. 110:4), and his chief responsibilities were to defend the powerless and to maintain justice, righteousness, and peace (e.g., Ps. 72; Isa. 9:7; 11:2-5)."¹⁰²