Ruler Priest Mentioned in the Bible by name

Melchisedec

Melchizedek, king of Salem [Jerusalem; Hebr. shalem means peace and wholeness], brought out bread and wine. He was a priest of God Most High (El Elion).
[The Hebrew name Malki-zedek means: "My king is righteous". See also Ps. 110; Heb. 5:6–10; 6:20–7:28. The connection between his name and the city is also found in the words "righteousness" and "peace." These two words are often found together, see Ps. 85:10; Isa. 9:7; 32:17; 48:18; 60:17.]

The Lord [Yahweh – God the Father] has made a promise (sworn an oath)
that he will not take back:
"You are a priest forever in the same way as Melchizedek."
[The Hebrew name Malkizedek means: "My king is righteous".]

He also says in another place:
You are a priest forever,
in the order of Melchizedek.
[Ps. 110:4. See also Heb. 7:1–10. Melchizedek was a priest and king, a contemporary of Abraham, see Gen. 14:17–24.]

and he was set apart (appointed) as high priest, a priest like Melchizedek (of the same rank).

Jesus entered there and opened the way for us:
when he became high priest forever,
in the same way as Melchizedek.
[Ps. 110:4; Heb. 5:6, 10; 7:1–17]

[The passage ends with the same quote from the Psalms that began this passage in Heb. 4:6. The main point is that a Christian must grow in faith and not remain immature. The warnings in the Epistle to the Hebrews follow an escalating pattern. If a believer begins to drift away from God's word, see Heb. 2:1–4, it leads to a hardened heart, see Heb. 3:7–4:13. This in turn leads to an unwillingness to listen, see Heb. 5:11–6:20. The solution is to hold fast to God and the hope that is likened to a firm anchor. The next paragraph goes on to explain how Melchizedek is a prototype of Jesus.]

[Melchizedek has been introduced in previous chapters. Now there is a more thorough review showing that he is a model for Jesus. Melchizedek is mentioned only twice in the Old Testament. He suddenly appears in the story of Abraham, see Gen. 14:18–20, and is quoted in Ps. 110, which is messianic. The first three verses of this chapter are a single verse in Greek.]
For this Melchizedek,
king of Salem [shortened form of Jerusalem, see Ps. 76:3],
priest of God Most High,
who met Abraham on his way back after his victory over the kings and blessed him,

because he existed as unborn in his ancestor's body
when Melchizedek met him.

If perfection could have been attained through the Levitical priesthood – and on that basis the [Jewish] people received the law [the teachings of the Books of Moses] – why did another priest have to arise, one like Melchizedek, one who is not said to be like Aaron?

It becomes even clearer when another priest like Melchizedek appears,

He receives the testimony:
You are a priest forever,
in the same way as Melchizedek.
[Ps. 110:4, this is the third time the same passage is quoted, see Heb. 5:6; 6:20.]