20 “And when he has made an end of atoning for the Holy Place and the tent of meeting and the altar, he shall present the live goat. 21 And Aaron shall lay both his hands on the head of the live goat, and confess over it all the iniquities of the people of Israel, and all their transgressions, all their sins. And he shall put them on the head of the goat and send it away into the wilderness by the hand of a man who is in readiness. 22 The goat shall bear all their iniquities on itself to a remote area, and he shall let the goat go free in the wilderness.
23 “Then Aaron shall come into the tent of meeting and shall take off the linen garments that he put on when he went into the Holy Place and shall leave them there. 24 And he shall bathe his body in water in a holy place and put on his garments and come out and offer his burnt offering and the burnt offering of the people and make atonement for himself and for the people. 25 And the fat of the sin offering he shall burn on the altar. 26 And he who lets the goat go to Azazel shall wash his clothes and bathe his body in water, and afterward he may come into the camp. 27 And the bull for the sin offering and the goat for the sin offering, whose blood was brought in to make atonement in the Holy Place, shall be carried outside the camp. Their skin and their flesh and their dung shall be burned up with fire. 28 And he who burns them shall wash his clothes and bathe his body in water, and afterward he may come into the camp.
29 “And it shall be a statute to you forever that in the seventh month, on the tenth day of the month, you shall afflict yourselves  and shall do no work, either the native or the stranger who sojourns among you. 30 For on this day shall atonement be made for you to cleanse you. You shall be clean before the Lord from all your sins. 31 It is a Sabbath of solemn rest to you, and you shall afflict yourselves; it is a statute forever. 32 And the priest who is anointed and consecrated as priest in his father's place shall make atonement, wearing the holy linen garments. 33 He shall make atonement for the holy sanctuary, and he shall make atonement for the tent of meeting and for the altar, and he shall make atonement for the priests and for all the people of the assembly. 34 And this shall be a statute forever for you, that atonement may be made for the people of Israel once in the year because of all their sins.” And Moses did as the Lord commanded him. (ESV)
 16:29 Or shall fast; also verse 31