Hebrews Chapter 7 introduces the Truth that the priesthood of Jesus Christ is superior to that of Aaron because “the order of Melchizedek” is superior to “the order of Levi.”
This Melchizedek was king of the city of Salem and also a priest of God Most High. (Hebrews 7:1 NLT)
Melchizedek was both king and priest. In the Old Testament, after the law was given, the two offices were never combined together - they were two separate offices.
King Uzziah of Judah is an example of a man who tried to combine the two offices, and paid the penalty for it - leprosy. 2 Chronicles 26:16-21 tells us the whole story.
Another person who tried to combine both the offices of king and priest was Saul – He was rejected by the Lord and lost his kingdom. 1 Samuel 13:8-14 tells us so
Then Abraham took a tenth of all he had captured in battle and gave it to Melchizedek. The name Melchizedek means “king of justice,” and king of Salem means “king of peace.” (Hebrews 7:2 NLT)
The name “Melchizedek” means “king of righteousness” or “king of justice” in the Hebrew language. The word Salem means “peace” (the Hebrew word shalom), so that Melchizedek is “king of peace” as well as “king of righteousness.”
“Righteousness” and “peace” are often found together in Scripture.
“The work of righteousness will be peace, and the effect of righteousness, quietness, and assurance forever.” (Isaiah 32:17)
“Mercy and truth have met together; righteousness and peace have kissed.” (Psalm 85:10)
True peace can be experienced only on the basis of righteousness.
If it were not for the finished work of Lord Jesus Christ on the cross, then it would not have been possible for righteousness and peace to have “‘kissed each other”.
Melchizedek received tithes from Abraham
Then Abraham took a tenth of all he had captured in battle and gave it to Melchizedek. (Hebrews 7:2)
This clearly shows us that tithing did not originate with Moses. Abraham practiced tithing long before the law was given.
There is no record of his father or mother or any of his ancestors—no beginning or end to his life. He remains a priest forever, resembling the Son of God. (Hebrews 7:3)
There is no record of his genealogy (“descent”) in the Old Testament, and this is significant because most great persons in the Old Testament have their ancestry identified. It was especially important that the priests be able to prove their ancestry (see Ezra 2:61–63; Nehemiah 7:63–65). In this way, he is a picture of the Lord Jesus Christ, the eternal Son of God.
Since there is no account of Melchizedek’s death, as far as the record is concerned, it seems that Melchizedek is still serving as a priest and king. This is another way in which he is like the eternal Son of God.
Consider then how great this Melchizedek was. Even Abraham, the great patriarch of Israel, recognized this by giving him a tenth of what he had taken in battle. (Hebrews 7:4)
In giving Melchizedek tithes and in receiving his blessing, Abraham affirmed the greatness of this king-priest.
And indeed those who are of the sons of Levi, who receive the priesthood, have a commandment to receive tithes from the people according to the law, that is, from their brethren, though they have come from the loins of Abraham (Hebrews 7:5)
The priesthood of Levi received tithes from Israel as a commandment. Abraham voluntarily gave tithes to Melchizedek. This makes Abraham’s giving to Melchizedek greater than Israel’s payment of tithes to the priesthood instituted by Moses.