"Melchizedek, king of Salem and priest of God Most High, met Abraham as he returned from his defeat of the kings and blessed him."
And Abraham apportioned to him "a... tenth of everything." His name first means righteous king, and he was also "king of Salem," that is, king of peace.
Without father, mother, or ancestry, without beginning of days or end of life, thus made to resemble the Son of God, he remains a priest forever.
It is even more obvious if another priest is raised up after the likeness of Melchizedek,
who has become so, not by a law expressed in a commandment concerning physical descent but by the power of a life that cannot be destroyed.
For it is testified: "You are a priest forever according to the order of Melchizedek."