Hebrews 6:13-7:10 New King James Version (NKJV)
God’s Infallible Purpose in Christ
13 For when God made a promise to Abraham, because He could swear by no one greater, He swore by Himself, 14 saying, “Surely blessing I will bless you, and multiplying I will multiply you.” 15 And so, after he had patiently endured, he obtained the promise. 16 For men indeed swear by the greater, and an oath for confirmation is for them an end of all dispute. 17 Thus God, determining to show more abundantly to the heirs of promise the [a]immutability of His counsel, [b]confirmed it by an oath, 18 that by two [c]immutable things, in which it is impossible for God to lie, we [d]might have strong consolation, who have fled for refuge to lay hold of the hope set before us.
19 This hope we have as an anchor of the soul, both sure and steadfast, and which enters the Presence behind the veil, 20 where the forerunner has entered for us, even Jesus, having become High Priest forever according to the order of Melchizedek.
The King of Righteousness
7 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.
4 Now consider how great this man was, to whom even the patriarch Abraham gave a tenth of the [e]spoils. 5 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; 6 but he whose genealogy is not derived from them received tithes from Abraham and blessed him who had the promises. 7 Now beyond all contradiction the lesser is blessed by the better. 8 Here mortal men receive tithes, but there he receives them, of whom it is witnessed that he lives. 9 Even Levi, who receives tithes, paid tithes through Abraham, so to speak, 10 for he was still in the loins of his father when Melchizedek met him.
Hebrews 6:13-7:10 New International Version (NIV)
The Certainty of God’s Promise
13 When God made his promise to Abraham, since there was no one greater for him to swear by, he swore by himself, 14 saying, “I will surely bless you and give you many descendants.”[a] 15 And so after waiting patiently, Abraham received what was promised.
16 People swear by someone greater than themselves, and the oath confirms what is said and puts an end to all argument. 17 Because God wanted to make the unchanging nature of his purpose very clear to the heirs of what was promised, he confirmed it with an oath. 18 God did this so that, by two unchangeable things in which it is impossible for God to lie, we who have fled to take hold of the hope set before us may be greatly encouraged. 19 We have this hope as an anchor for the soul, firm and secure. It enters the inner sanctuary behind the curtain, 20 where our forerunner, Jesus, has entered on our behalf. He has become a high priest forever, in the order of Melchizedek.
Melchizedek the Priest
7 This Melchizedek was king of Salem and priest of God Most High. He met Abraham returning from the defeat of the kings and blessed him, 2 and Abraham gave him a tenth of everything. First, the name Melchizedek means “king of righteousness”; then also, “king of Salem” means “king of peace.” 3 Without father or mother, without genealogy, without beginning of days or end of life, resembling the Son of God, he remains a priest forever.
4 Just think how great he was: Even the patriarch Abraham gave him a tenth of the plunder! 5 Now the law requires the descendants of Levi who become priests to collect a tenth from the people—that is, from their fellow Israelites—even though they also are descended from Abraham. 6 This man, however, did not trace his descent from Levi, yet he collected a tenth from Abraham and blessed him who had the promises. 7 And without doubt the lesser is blessed by the greater. 8 In the one case, the tenth is collected by people who die; but in the other case, by him who is declared to be living. 9 One might even say that Levi, who collects the tenth, paid the tenth through Abraham, 10 because when Melchizedek met Abraham, Levi was still in the body of his ancestor.