Leviticus 23:23-27

23And Jehovah spake unto Moses, saying, 24Speak unto the children of Israel, saying, In the seventh month, on the first day of the month, shall be a solemn rest unto you, a memorial of blowing of trumpets, a holy convocation. 25Ye shall do no servile work; and ye shall offer an offering made by fire unto Jehovah.

26And Jehovah spake unto Moses, saying, 27Howbeit on the tenth day of this seventh month is the day of atonement: it shall be a holy convocation unto you, and ye shall afflict your souls; and ye shall offer an offering made by fire unto Jehovah.