Psalm 110 and Covenantal Faithfulness in the Eschatological Role of a Faithful Priest

The eschatological role of a faithful priest is first mentioned in a prophecy from Samuel: “I will raise up for myself a faithful priest, who shall do according to what is in my heart and in my mind” (1 Sam 2:35a, English Standard Version). Remarkably, the two oracles in Psalm 110, based on the structure and progressive development of priestly covenants associated with the prophecy of a faithful priest, have the nature and function of the priesthood in the Old Testament. The “priest” mentioned in Psalm 110: 4b refers to a priest-king like Melchizedek, but the “priest” in 1 Samuel 2:35a refers to the line of Aaron. This dissertation will develop a biblical-theological rationale to explore the union of priesthood and kingship in Psalm 110 through the context of selected passages fulfilled in part and entirety in the eschatological kingdom. The role of a faithful priest applies the tone of Yahweh’s faithfulness to the future ministry of a priest-king in the line of David. It is an ethical imperative rooted in the law of God. Although some disobedient and unfaithful descendants of Aaron, like Elides, fell short in their duties (1 Sam 2:17–22), the Levitical priesthood remains inextinguishable under God’s mandate. Psalm 110:4 echoes the same sequential essence of priesthood prophesied in 1 Samuel 2:35a, yet still points to a similar role of a faithful priest by changing the order of the priestly line. This same priestly responsibility of the Levitical priesthood is also applied in the context of Psalm 110 to shape the union of the priesthood and kingship. The concept of merging the two offices eliminates the confusion of mingling the roles of priests and kings in the eschatological kingdom. The trajectory of developing the big picture of a priest-king Messiah in Psalm 110 is God’s providential plan that the Anointed One is both priest and king. This underscores the same expectation promised for a faithful priest in 1 Samuel 2:35a. This psalm is the capstone of the prophetic prediction of God’s covenantal faithfulness in priesthood and kingship found in Psalm 110. It underscores Christ’s high priest status, which oversees priestly responsibilities that Yahweh promised faithful priests in the new covenant relationship. Thus, the universal role of one future Davidic king becoming a designee as an ultimate priest-king will end the power play between the priests and the kings. The coming Davidic descendant with the functional ability of the priestly order will have authority over the Levitical priests as a high priest (Ezek 40–43). Millennial priests in the line of Zadok, Aaron’s descendant, will faithfully serve the Messiah by performing ministerial duties in the coming Millennial Kingdom.