Hebrews 7:1-5
Heb 7:1 (KJB)
For this Melchisedec, king of Salem, priest of the most high God, who met Abraham returning from the slaughter of the kings, and blessed him;
Melchisedec - His name means King of Righteousness
Salem - Peace
This verse begins by taking us back to Genesis 14 when Abraham had returned from freeing his nephew Lot when he was taken in battle when 4 kings had caused the kings of Sodom and Gomorrah to go on the run, the other kings had plundered Sodom and Gomorrha and in that plundering they took Lot captive. Abraham had mustered all those who were with him and attacked and freed Lot. On the way back from that battle he was met by Melchisedec who was a priest of the Most High God. Melchisedec had blessed Abraham and in Genesis 14:19 had also blessed the Lord God of Heaven. (Gen 14:19 KJV) And he blessed him, and said, Blessed be Abram of the most high God, possessor of heaven and earth: The two names describing Melchisedec play an important part in the true identification of who this is.
Heb 7:2 (KJB)
To whom also Abraham gave a tenth part of all; first being by interpretation King of righteousness, and after that also King of Salem, which is, King of peace;
Here we see that Abraham gave a tithe to this king and we also have the meanings of the names of Melchisedec opened to us. As we have previously seen it is King of Righteousness and King of Peace. These titles could never be given to an earthly king because they intimate something much deeper than just a name. Righteousness is something the Lord Jesus Christ imputes to the believer when they become saved. Peace is also something which the Lord Jesus Christ gives to the believer upon salvation. (James 3:18 KJV) And the fruit of righteousness is sown in peace of them that make peace. James teaches us that both peace and righteousness dwell in the believer and only the Lord Jesus Christ can be king of each. Abraham gave a tithe to this person and the Bible speaks about giving a tithe but it is to be given unto the Lord. (Lev 27:30 KJV) And all the tithe of the land, whether of the seed of the land, or of the fruit of the tree, is the LORD'S: it is holy unto the LORD. Nowhere in Scripture are we commanded to give a tithe to an earthly king because the tithe was a spiritual offering.
Heb 7:3 (KJB)
Without father, without mother, without descent, having neither beginning of days, nor end of life; but made like unto the Son of God; abideth a priest continually.
Without descent - Without genealogy
Continually - Perpetuity
There are only two people in history who did not have a mother and father and that was Adam and Eve. Here we see that Melchisedec did not have mother or father. Now it may also be believed that like the Lord Jesus Christ who came out of the tribe of Judah where there was no priestly lineage, Melchisedec also was not of a priestly lineage. Now I would not know what priestly line he would have been in view since the Levitical priesthood was not yet to begin for another 600 years. The verse states that he was made like unto the Son of God. In Daniel there is a similar description. (Dan 3:25 KJV) He answered and said, Lo, I see four men loose, walking in the midst of the fire, and they have no hurt; and the form of the fourth is like the Son of God.  Christ had come to the aid of Shadrach, Meshach, and Abednego and is described as “the fourth is like the Son of God.” In Hebrews 7:3 we have the same type of description. Melchisedec is said to have no beginning of days and no end of days.  (Micah 5:2 KJV) But thou, Bethlehem Ephratah, though thou be little among the thousands of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel; whose goings forth have been from of old, from everlasting. Only Christ has no beginning and no end of days, and since this Priest of the Most High God serves in perpetuity, it can only mean that the person in view here is Christ who fits both titles of King of Righteousness and Peace. This means that it was Christ in a Christophany (pre-Bethlehem appearance of Christ) who met Abraham on the way.
Heb 7:4 (KJB)
Now consider how great this man was, unto whom even the patriarch Abraham gave the tenth of the spoils.
Here we are told that Abraham gave a tenth of all the spoils to Melchisedec. I believe deeply it was Christ who gave Abraham the victory over the four kings. Abraham had only 318 men which made that a small band compared to armies of four cities. Just as God gave Gideon the victory over the Midianites with 300, so the Lord Jesus Christ gave victory to Abraham with just 318.
(Gen 14:8-10 KJV) And there went out the king of Sodom, and the king of Gomorrah, and the king of Admah, and the king of Zeboiim, and the king of Bela (the same is Zoar;) and they joined battle with them in the vale of Siddim; {9} With Chedorlaomer the king of Elam, and with Tidal king of nations, and Amraphel king of Shinar, and Arioch king of Ellasar; four kings with five. {10} And the vale of Siddim was full of slimepits; and the kings of Sodom and Gomorrah fled, and fell there; and they that remained fled to the mountain.
Abraham was giving this tenth of his spoils as a gift unto the Lord for the deliverance of Lot and the victory over the 4 kings.
Heb 7:5 (KJB)
And verily they that are of the sons of Levi, who receive the office of the priesthood, have a commandment to take tithes of the people according to the law, that is, of their brethren, though they come out of the loins of Abraham:
According to the Mosaic Law it was the Levites who were to tend to the service of the Tabernacle and Temple and were to collect tithes from the people. This commandment of tithes came about 600 years after the time of Abraham. (Num 18:28 KJV) Thus ye also shall offer an heave offering unto the LORD of all your tithes, which ye receive of the children of Israel; and ye shall give thereof the LORD'S heave offering to Aaron the priest. Here is an interesting parallel. When the priests received the tithes from all the children of Israel, the priests were then to give the heave offering to Aaron the High Priest. This is exactly what Abraham did, he gave the tithe of all the spoils to Melchisedec as the priests gave the heave offering to Aaron.