This Melchizedek was the king of Salem and a priest of God Most High. When Abraham was coming back from winning a battle against a group of kings, Melchizedek met him and blessed him.
Abraham gave him a tenth of everything he’d captured in the battle. First, the name Melchizedek means “king of what is right.” Then, “king of Salem” means “king of peace.”
Melchizedek didn’t trace his family line from Levi, but he still collected a tenth from Abraham. Melchizedek blessed the one who had received the promises.