And Aaron shall make an atonement upon the horns of it once in a year with the blood of the sin offering of atonements: once in the year shall he make atonement upon it throughout your generations: it [is] most holy unto the Lord. (30:10)

--Leviticus--

Also on the tenth [day] of this seventh month [there shall be] a day of atonement: it shall be an holy convocation unto you; and ye shall afflict your souls, and offer an offering made by fire unto the Lord. (23:27)

Then shalt thou cause the trumpet of the jubilee to sound on the tenth [day] of the seventh month, in the day of atonement shall ye make the trumpet sound throughout all your land. (25:9)

--Numbers--

And ye shall have on the tenth [day] of this seventh month an holy convocation; and ye shall afflict your souls: ye shall not do any work [therein]: (29:7)