Leviticus 23:23-27

23Again the Lord spoke to Moses, saying,

24“Say to the children of Israel, ‘On the first day of the seventh month (almost October), you shall observe a day of solemn sabbatical rest, a memorial day announced by the blowing of trumpets, a holy convocation.

25You shall not do any laborious work [on that day], but you shall present an offering by fire to the Lord.’ ”

26The Lord spoke to Moses, saying,

27“Also the tenth day of this seventh month is the Day of Atonement; it shall be a holy convocation for you, and you shall humble yourselves [by fasting] and present an offering by fire to the Lord.