Leviticus 23:26

Speak unto the children of Israel, saying, In the seventh month, in the first [day] of the month, shall ye have a sabbath, a memorial of blowing of trumpets, an holy convocation.

Ye shall do no servile work [therein]: but ye shall offer an offering made by fire unto the LORD.

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.

And ye shall do no work in that same day: for it [is] a day of atonement, to make an atonement for you before the LORD your God.