Exodus 29:30

29:30 The priest who succeeds him from his sons, when he first comes to the tent of meeting to minister in the Holy Place, is to wear them for seven days.

Exodus 29:37

29:37 For seven days you are to make atonement for the altar and set it apart as holy. Then the altar will be most holy. Anything that touches the altar will be holy.

Exodus 40:12-13

40:12 “You are to bring Aaron and his sons to the entrance of the tent of meeting and wash them with water. 40:13 Then you are to clothe Aaron with the holy garments and anoint him and sanctify him so that he may minister as my priest.

Leviticus 8:33-35

8:33 And you must not go out from the entrance of the Meeting Tent for seven days, until the day when your days of ordination are completed, because you must be ordained over a seven-day period. 8:34 What has been done on this day the Lord has commanded to be done to make atonement for you. 8:35 You must reside at the entrance of the Meeting Tent day and night for seven days and keep the charge of the Lord so that you will not die, for this is what I have been commanded.”

Leviticus 14:8-11

The Seven Days of Purification

14:8 “The one being cleansed must then wash his clothes, shave off all his hair, and bathe in water, and so be clean. Then afterward he may enter the camp, but he must live outside his tent seven days. 14:9 When the seventh day comes he must shave all his hair – his head, his beard, his eyebrows, all his hair – and he must wash his clothes, bathe his body in water, and so be clean.

The Eighth Day Atonement Rituals

14:10 “On the eighth day he must take two flawless male lambs, one flawless yearling female lamb, three-tenths of an ephah of choice wheat flour as a grain offering mixed with olive oil, and one log of olive oil, 14:11 and the priest who pronounces him clean will have the man who is being cleansed stand along with these offerings before the Lord at the entrance of the Meeting Tent.