What is the context?
This quotation from Psalm 110:4 supports the preceding statement that Jesus did not appoint Himself high priest. God gives Him a priesthood described as enduring forever.
Melchizedek appears in Genesis 14:18–20 as a king and priest who blesses Abraham. Hebrews will develop the connection in chapter 7. The word order here concerns the manner of priesthood; it does not establish that Jesus descended through a bloodline from Melchizedek.
How is this passage commonly understood?
Calvin, Wesley and the Catholic Catechism, paragraph 1544, recognize Melchizedek as pointing to Christ’s unique priesthood. The promise concerns a priest who endures, rather than a succession created by Jesus’ own ambition.
Traditions differ over ordained priesthood in the church. The Catholic Catechism, 1545–1547, understands ministers as participating in Christ’s one priesthood and making His unique sacrifice present in the Eucharist, the church’s celebration of the Lord’s Supper. Reformed teaching in the Westminster Confession, 29.1–2, understands the Lord’s Supper as commemorating His once-for-all offering and rejects a further sacrifice for sin. Both affirm the uniqueness of Christ’s sacrifice, while explaining the church’s ministry differently.
Where does this fit in God's plan?
Hebrews 7:11–17 explains why the promise reaches beyond the priesthood associated with Levi: Jesus’ priesthood is grounded in an indestructible life. The earlier king-priest provides the comparison Hebrews itself draws.
Hebrews 7:24–25 then states the result for those coming to God through Him. His priesthood continues because He lives forever. The promise serves God’s purpose of giving His people lasting access through Christ.
What is our position?
Our study Who Shepherds the Church? reads Christ’s priesthood as permanent: He needs no successor, and believers approach God through Him. It therefore rejects a clergy class functioning as the necessary spiritual mediator between believers and God, while affirming the work of elders who teach and care for the church.