Exodus 29:9

9and you shall gird Aaron and his sons with asashes and bind caps on them. And bthe priesthood shall be theirs by a statute forever. Thus you shall cordain Aaron and his sons.

Exodus 40:15

15 dand anoint them, as you anointed their father, that they may serve me as priests. And their anointing shall admit them to a eperpetual priesthood throughout their generations.”

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