‘Then Melchizedek king of Salem brought out bread and wine. He was priest of God Most High, and he blessed Abram, saying,
“Blessed be Abram by God Most High,
Creator of heaven and earth.
And praise be to God Most High,
Who delivered your enemies into your hand”
Then Abram gave him a tenth of everything.’ (Genesis 14:18-20).
We are told Melchizedek was king of Salem and also a priest. Melchizedek is the first priest to be mentioned in the Bible. He is called priest of El-Elyon, El-Elyon is one of the titles for God that is used by Abram and the patriarchs. Melchizedek is a priest before the Levitical priesthood was set up. We see Melchizedek bless Abram which is the first blessing since the promises made in 12:1-3 (that Abram would be a great nation and that God will bless those who bless him, ie Melchizedek). The reason I wanted to focus on Melchizedek here is that he is a very important figure in Hebrews. Hebrews says:
[Jesus] was designated by God to be high priest in the order of Melchizedek. (Heb 5:10)
and then goes on (in Heb 7) to use these verses from Genesis to show that Jesus’ priesthood is superior to the Levitical priesthood because Abram gave a tenth of everything to Melchizedek (Gen 14:20).
‘Levi himself, who receives tithes, paid tithes through Abraham, for he was still in the loins of his ancestor when Melchizedek met him’ (Heb 7:9-10).
So the priesthood of Melchizedek is superior to the Levitical one because in essence Levi paid tithes to Melchizedek. What is more, Hebrews says,
It is beyond dispute that the inferior is blessed by the superior (Heb 7:7).
So because Melchizedek blessed Abram that shows him to be superior to him and therefore his offspring. This Genesis passage is part of the foundation of why we hold Jesus to be our High Priest even though he was not from the Levitical line and therefore could not be a priest under the law. Jesus is a superior High Priest in the order of Melchizedek.