'Perpetually' in the Bible
Without father, without mother, without genealogy, having neither beginning of days nor end of life, but made like the Son of God, he remains a priest perpetually.
Furthermore, here [in the Levitical priesthood] tithes are received by men who are subject to death; but in that case [concerning Melchizedek], they are received by one of whom it is testified that he lives on [perpetually].
The [former successive line of] priests, on the one hand, existed in greater numbers because they were each prevented by death from continuing [perpetually in office];