Exodus 21:19

21:19 and then if he gets up and walks about outside on his staff, then the one who struck him is innocent, except he must pay for the injured person’s loss of time and see to it that he is fully healed.

Exodus 27:21

27:21 In the tent of meeting outside the curtain that is before the testimony, Aaron and his sons are to arrange it from evening to morning before the Lord. This is to be a lasting ordinance among the Israelites for generations to come.