Leviticus 16:29-34

The Day of Atonement is a day of rest

29 On the tenth day of the seventh month, you must not eat and you must not do any work. This is a rule that you must obey every year for all time. It is a rule for you who belong to Israel's people and for foreign people who live among you. 30 It will be the Day of Atonement. On this day the priest will make you clean. The Lord will forgive you for all your sins. 31 It is a very holy day of complete rest for you. You must not eat during that day. This is a rule that you must all obey every year.

32 The descendant of Aaron who is chosen as leader of the priests will do all these things on the Day of Atonement. He will put on the linen clothes that are holy. 33 He will make clean the Most Holy Place, the Tent of Meeting and the altar. He will make the priests and all the people clean from their sins. 34 Once every year, on this day, he will make Israel's people clean from all their sins. This is a rule that you must obey for all time.’

Moses did all these things as the Lord had commanded him.