Leviticus 23:23-27

23And the Lord spake unto Moses, saying, 24Speak 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. 25Ye shall do no servile work therein: but ye shall offer an offering made by fire unto the Lord.

26And the Lord spake unto Moses, saying, 27Also 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.