Called and appointed
Every high priest chosen from among mortals is put in charge of things pertaining to God on their behalf, to offer gifts and sacrifices for sins. He is able to deal gently with the ignorant and wayward, since he himself is subject to weakness; and because of this he must offer sacrifice for his own sins as well as for those of the people. And one does not presume to take this honor, but takes it only when called by God, just as Aaron was.
So also Christ did not glorify himself in becoming a high priest, but was appointed by the one who said to him,
“You are my Son, today I have begotten you”;
as he says also in another place,
“You are a priest forever, according to the order of Melchizedek.”
In the days of his flesh, Jesus offered up prayers and supplications, with loud cries and tears, to the one who was able to save him from death, and he was heard because of his reverent submission. Although he was a Son, he learned obedience through what he suffered; and having been made perfect, he became the source of eternal salvation for all who obey him, having been designated by God a high priest according to the order of Melchizedek.~ Hebrews 5:1-10
When I went through the Candidacy process in our Synod to ultimately be commissioned (and later ordained) as a Deacon for the ELCA, there were many steps along the way to make sure that it was not just myself (and my ego) deciding this was my call.
There were steps along the way to make sure that I was not out to glorify myself, but that I had a true call.
In the Hebrew scriptures there were generally speaking two types of priests mentioned: priests in the order of Aaron, and priests in the order of Melchizedek.
Priests from the order of Aaron (also Levitical priests) were appointed and served to mediate between the people and God through the Mosaic Law. They served by the Lord's call and were explicitly not to glorify themselves.
There was only one priest of the Melchizedek order. He was the King of Salem (later Jerusalem) and had an encounter with Abraham where he blessed him. A priest from the order of Melchizedek would serve as the original priest Melchizedek served: as both king and priest.
There is only one of those: Jesus, the Christ.
And yet even with this impressive title, Jesus does not glorify himself. (and he didn't even need a Candidacy committee to make sure he didn't!)
Holy One, give me trustworthy voices that help me to hear your call. Amen