Genesis 14:18 says that Abraham used a priest named Mechizidec.
Judah has no priests but Yeshua is of the Order of Melchizidec (Hebrews 7:14).
Psalm 110 says the Messiah is a priest of the Order of Melchizidek.
What do Orthodox Jews say about this?
I also believe that in a certain passage in 2nd Samuel describes that the high priest is crowned and sits on a throne. But how can this be? How can a priest be a king at the same time?
Probably the same way a person gained the title, "Doctor of the Law".