By setting forth the superiority of Jesus’ high priesthood, the author of Hebrews sought to prove his thesis that during times of testing believers should look to Jesus for help. The flow of thought in Hebrews 5-7 would not be valid if both the author and the audience had not understood the Old Testament itself as a valid witness of God’s historical dealings with humanity. The author understood the Old Testament in light of Christ, and the storyline of redemptive history.
(1) In Heb 5:5, the author applied Ps 2:7 to Jesus in order to reinforce that God had addressed Jesus as His Son, authenticating the Son’s priestly ministry on earth. In Psalm 2, the psalmist portrayed Israel’s King as God’s representative on earth. God anointed the King and addressed the King as His Son (Ps 2:2, 7). From Mount Zion, God’s anointed King ruled with might (Ps 2:6-9). Thus, in vain the leaders of the earth took their stand against the Lord and His Son Who ruled as King (Ps 2:2). In Hebrews 1-2, the author compared Jesus to angels and argued that God’s revelatory work in Jesus surpassed what He had given through angels. The author cited Ps 2:7 in Heb 1:5 to accentuate his point. He wrote, “For to which of the angels did He ever say, ‘You are My Son; today I have become Your Father.” In the author of Hebrews’ logic, Ps 2:7 was God’s word to Jesus seated at His right hand. The author of Hebrews also saw in Ps 2:7 God’s word confirming Jesus’ priestly authority. In Heb 5:1-4, the author noted that priests in the old covenant dealt mercifully with the people because the priests themselves also had sins for which they had to offer sacrifices. Serving as a priest was an honorable mediatorial task as the priest stood between God and man and lived to tell about it. No man took the priestly office for himself but had to be called by God to stand before God on behalf of sinners. Jesus too, the author of Hebrews wrote, did not of Himself become a high priest who would lay down His life for the sins of the people (Heb 2:17-18; 4:14-16). Instead, in accord with Ps 2:7, God said to Jesus, “You are My Son; today I have become Your Father” (Heb 5:5).
(2) In Heb 5:6; 6:20; 7:17, 21 the author applied Ps 110:4 to Jesus in order to portray God’s oath that Jesus is an eternal priest. The author of Psalm 110 recorded God’s oath which established Israel’s king in a place of political and religious authority over the nation. The king is seated at God’s right hand (Ps 110:1) and God is at his right hand (Ps 110:5). God promised that the king would rule with power over his enemies, crushing foreign kings when God expressed His wrath against them through the king He placed over Israel (Ps 110:2-3, 5-6). The Lord swore to the king that he would serve not only as Israel’s ruler but Israel’s priest forever, in accord with Melchizedek’s eternal priesthood (Ps 110:4). In Gen 14:17-24, Melchizedek served as the priest to God Most High in Salem. Melchizedek blessed Abraham when the patriarch returned from rescuing Lot from a cohort of kings that attacked the region of Sodom and Gomorrah. Melchizedek was recognized as a priest even before the Lord established Aaron and the Levites as priests. Melchizedek had no genealogy and was thus an eternal priest. In Heb 5:6, the author of Hebrews appended Ps 110:4, “You are a priest forever in the order of Melchizedek,” to his citation of Ps 2:7 in order to underscore that God Himself swore Jesus into His office as an eternal High Priest. The author of Hebrews quoted Ps 110:4 in Heb 7:21 to reinforce his point: God swore an oath that Jesus is an eternal High Priest. Jesus performed His priestly ministry on earth at the cross but because He is an eternal priest, He yet serves as an advocate for believers in heaven (Heb 6:20). Melchizedek was an eternal priest because he had no genealogy and the author of Genesis recorded no date of birth or death; Jesus serves as an eternal priest because He has an indestructible life (Heb 7:16-17).
(3) In Heb 6:14, the author quoted Gen 22:17 to encourage his audience in God’s faithfulness to His promise of blessing. In Genesis 22, the Lord told Abraham to go to Mount Moriah and there offer the sacrifice of his son, his only son, Isaac. Abraham obeyed God, willing to sacrifice the child of promise. When Abraham raised his hand to slay his son on the altar, the angel of the Lord intervened and stopped Abraham from completing the sacrifice. Abraham had passed the test of faith. The Lord swore an oath that He would bless the patriarch with many offspring because Abraham feared the Lord and obeyed His word when tested (Gen 22:17-18). The author of Hebrews was concerned that his friends endure to inherit the promises they had received in the new covenant (Heb 12:25-29; 13:10-14). In order to explain the stability of God’s promises—and encourage the congregation’s perseverance—he described God’s faithfulness to Abraham when He swore that He would bless and multiply Abraham’s descendants (Heb 6:14).