Chapter 7 of Hebrews begins with “1 For this Melchizedek, king of Salem, priest of the Most High God, who met Abraham returning from the slaughter of the kings and blessed him, 2 to whom also Abraham gave a tenth part of all, first being translated “king of righteousness,” and then also king of Salem, meaning “king of peace,” 3 without father, without mother, without genealogy, having neither beginning of days nor end of life, but made like the Son of God, remains a priest continually.”

I don’t understand someone being without a father or mother or genealogy.  My Amplified version in verse 8 “8Furthermore, here [in the Levitical priesthood] tithes are received by men who are subject to death; while there [in the case of Melchizedek], they are received by one of whom it is testified that he lives [perpetually].”

How can a high priest live perpetually?  I don’t know.  But the author of Hebrews is building up to the fact that Jesus is our High Priest.

Hebrews 7:24-26 “24But He holds His priesthood unchangeably, because He lives on forever.

25Therefore He is able also to save to the uttermost (completely, perfectly, finally, and for all time and eternity) those who come to God through Him, since He is always living to make petition to God and intercede with Him and intervene for them.

26[Here is] the High Priest [perfectly adapted] to our needs, as was fitting--holy, blameless, unstained by sin, separated from sinners, and exalted higher than the heavens.”  Amplified Version

Abraham gave a tenth portion of the spoil, after slaughtering some kings, to Melchizedek because he had blessed him; and (I think) it was the first time in the bible that someone gave a tenth portion of anything.  The next time was when Jacob did it, below.

Genesis chapter 28:10-22 Jacob’s Vow at Bethel

10 Now Jacob went out from Beersheba and went toward Haran. 11 So he came to a certain place and stayed there all night, because the sun had set. And he took one of the stones of that place and put it at his head, and he lay down in that place to sleep. 12 Then he dreamed, and behold, a ladder was set up on the earth, and its top reached to heaven; and there the angels of God were ascending and descending on it.

13 And behold, the Lord stood above it and said: “I am the Lord God of Abraham your father and the God of Isaac; the land on which you lie I will give to you and your descendants. 14 Also your descendants shall be as the dust of the earth; you shall spread abroad to the west and the east, to the north and the south; and in you and in your seed all the families of the earth shall be blessed. 15 Behold, I am with you and will keep you wherever you go, and will bring you back to this land; for I will not leave you until I have done what I have spoken to you.”

16 Then Jacob awoke from his sleep and said, “Surely the Lord is in this place, and I did not know it.” 17 And he was afraid and said, “How awesome is this place! This is none other than the house of God, and this is the gate of heaven!”

18 Then Jacob rose early in the morning, and took the stone that he had put at his head, set it up as a pillar, and poured oil on top of it. 19 And he called the name of that place Bethel; but the name of that city had been Luz previously. 20 Then Jacob made a vow, saying, “If God will be with me, and keep me in this way that I am going, and give me bread to eat and clothing to put on, 21 so that I come back to my father’s house in peace, then the Lord shall be my God. 22 And this stone which I have set as a pillar shall be God’s house, and of all that You give me I will surely give a tenth to You.”

And that’s one reason why we are supposed to give a tenth of our earnings to the storehouse of God, called tithing.  The following Scriptures from Malachi 3:7-18 are because God says so!

“7Even from the days of your fathers you have turned aside from My ordinances and have not kept them. Return to me, and I will return to you, says the Lord of hosts. But you say, How shall we return?

8Will a man rob or defraud God? Yet you rob and defraud Me. But you say, In what way do we rob or defraud You? [You have withheld your] tithes and offerings.

9You are cursed with the curse, for you are robbing Me, even this whole nation.

10Bring all the tithes (the whole tenth of your income) into the storehouse, that there may be food in My house, and prove Me now by it, says the Lord of hosts, if I will not open the windows of heaven for you and pour you out a blessing, that there shall not be room enough to receive it.

11And I will rebuke the devourer [insects and plagues] for your sakes and he shall not destroy the fruits of your ground, neither shall your vine drop its fruit before the time in the field, says the Lord of hosts.

12And all nations shall call you happy and blessed, for you shall be a land of delight, says the Lord of hosts.

13Your words have been strong and hard against Me, says the Lord. Yet you say, What have we spoken against You?

14You have said, It is useless to serve God, and what profit is it if we keep His ordinances and walk gloomily and as if in mourning apparel before the Lord of hosts?

15And now we consider the proud and arrogant to be happy and favored; evildoers are exalted and prosper; yes, and when they test God, they escape [unpunished].

16Then those who feared the Lord talked often one to another; and the Lord listened and heard it, and a book of remembrance was written before Him of those who reverenced and worshipfully feared the Lord and who thought on His name.

17And they shall be Mine, says the Lord of hosts, in that day when I publicly recognize and openly declare them to be My jewels (My special possession, My peculiar treasure). And I will spare them, as a man spares his own son who serves him.

18Then shall you return and discern between the righteous and the wicked, between him who serves God and him who does not serve Him.” Amplified Version