Leviticus 16:29-34

“This law will always continue for you: On the tenth day of the seventh month, you must deny yourself and you must not do any work. The travelers or foreigners living with you must not work either. It is on this day that the priests will make you clean so you will belong to the LORD again. All your sins will be removed. This is a very important day of rest for you, and you must deny yourselves. This law will continue forever. “The priest appointed to take his father’s place, on whom the oil was poured, will perform the acts for making things ready for service to the LORD. He must put on the holy linen clothes and make the Most Holy Place, the Meeting Tent, and the altar ready for service to the LORD. He must also remove the sins of the priests and all the people of Israel so they will belong to the LORD. That law for removing the sins of the Israelites so they will belong to the LORD will continue forever. You will do these things once a year.” So they did the things the LORD had commanded Moses.