(Hebrew: king of justice)
King of Salem, most probably Jerusalem, and a priest of the Most High God.
He came to meet Abram after his victory over Chodorlahomor and his allies (Genesis 14), and on this occasion brought forth bread and wine, blessed Abram, thanked God for the victory, and received tithes of all the spoils.
The "bringing forth bread and wine" is interpreted by all the Fathers and Catholic commentators as offering a sacrifice to God, because the phrase which follows, "he was priest of the Most High God," seems to give the motive why he brought forth bread and wine.
According to oriental custom Abram would wish to thank God by sacrifice, and if Melchisedech came to meet Abram because he was a priest of the Most High God, the latter would ask him to offer the sacrifice, and would pay him the tithes for this truly sacerdotal function.
Melchisedech is a type of Christ (Psalm 109; Hebrews 7), because of his titles, King of Justice, King of Peace, Priest of the Most High God; and because of his eternal priesthood.
Scripture is silent about his lineage, about his birth and death; and in this sense he is "without father, without mother, without genealogy, having neither beginning of days nor end of life" (Hebrews 7).
This silence suggests the eternal Son of God and His endless priesthood.
He is a type of Christ also because of his superiority to Abram, from whom he received tithes and whom he blessed.
In Jewish tradition Melchisedech is commonly identified with Sem; Origen and Didymus held him to have been an angel; some even thought that he Wall an incarnation of the Holy Spirit or the Son of God.
New Catholic Dictionary