28 For the law appoints as high priests men who have weakness, but the word of the oath, which came after the law, appoints the Son who has been perfected forever.
Verse 28 shows the profound difference between Christ’s priesthood and the Levitical.
The “for” gives the reason for the differences between Christ’s and Levitical priesthoods.
the law appoints as high priests men who have weakness,
The Mosaic law appointed high priests with “weakness.” They were morally and spiritually weak.
but the word of the oath,
Jesus’ priesthood came by an “oath” confirmed by God (Ps 110:4). If the Levitical priesthood had been permanent, then there would be no further need for a priesthood.
which came after the law,
The Melchizedekian oath in Psalm 110:4 came centuries after Moses and the law. Jesus came in the line of David and the Davidic oath in this verse and the Davidic Covenant in 2 Samuel 7:12–18. Christ’s priesthood abrogated the preceding Levitical priesthood.
appoints the Son
A second difference in priesthoods is that Jesus’ was as the “Son” of God. Since He shares the very nature of God, His priesthood is eternal in nature.
who has been perfected forever.
The words “perfected forever” refer to the consecration and completion of the requirements for Christ’s priesthood. The thought is that He was consecrated or fully installed in priestly office. In His humanity He met every prerequisite to save and deliver us (He 2:10, 17–18; 4:15–16; 5:8). It is by the completion of Christ’s work on the cross that He made our salvation possible. Therefore, who and what He is suits us and is appropriate for us.
“Perfected” does not carry the idea that He was morally imperfect in some sense. Jesus never became morally perfect; He was perfect forever as the Son of God.
Jesus is the ideal High Priest.
This chapter climaxes with high Christology about the Son. This is the One who made the universe (He 1:2). He is the radiance of God’s glory and the exact representation of His being. He made purification for our sins (He 1:3). This High Priest passed through the heavens (He 4:14). Thus, as the divine and pre-existent Son of God living forever, He stands in a unique place to function as our permanent High Priest.