Hebrews 5:6 - Ellicott's Commentary On The Whole Bible

Thou art a priest for ever... — On Psalms 110 see the Note on Hebrews 1:13. The fourth verse, here quoted, is the kernel of the Psalm, and supplies the theme for a large portion of this Epistle, especially Hebrews 7. As the promise of 2 Samuel 7 was the prelude to the revelation of the second Psalm, the divine declaration recorded in Exodus 19:6 may have prepared the way for the promise of Psalms 110:4. The king of Israel was the type of the Son of David; and in the consecrated people, who, had they been faithful, would have remained the representatives of all nations before God, was dimly foreshadowed the Anointed Priest.