Christ Was Like unto Melchizedek
Psalm 110:4
4 The Lord hath sworn, and will not repent, Thou art a priest for ever after the order of Melchizedek.
Elder Bruce R. McConkie wrote:
“One of the great Messianic prophecies, spoken by the mouth of David, says: ‘The Lord hath sworn, and will not repent, Thou art a priest for ever after the order of Melchizedek.’ (Ps. 110:4.) Paul names Christ as the ‘High Priest of our profession’ (Heb. 3:1), who came in fulfillment of David’s prophecy; shows that His coming involved the receipt of a different priesthood than that held by the Levites; and says that Christ came ‘after the similitude of Melchisedec’ (Heb. 7:15). It appears that Paul’s statement—‘Who in the days of his flesh, when he had offered up prayers and supplications with strong crying and tears unto him that was able to save him from death, and was heard in that he feared; Though he were a Son, yet learned he obedience by the things which he suffered’ (Heb. 5:7–8)—has reference both to Melchizedek and to Christ, which harmonizes with the concept that Christ was like unto Melchizedek.”
(The Promised Messiah: The First Coming of Christ [1978], 450–51.)