'Priesthood' in the Bible

Tell all the skilled and talented people whom I have endowed with a spirit of wisdom, that they are to make Aaron’s garments to sanctify him and set him apart to serve as a priest for Me.

Tie the sashes on Aaron and his sons and fasten headbands on them. The priesthood is to be theirs by a permanent statute. This is the way you will ordain Aaron and his sons.

the woven garments as well, and the holy garments for Aaron the priest, and the garments of his sons, with which to carry on their priesthood;

And thou shalt anoint them, as thou didst anoint their father, that they may minister unto me in the priest's office: for their anointing shall surely be an everlasting priesthood throughout their generations.