Leviticus 23:23-27

Again the Lord spoke to Moses, saying,

“Speak to the sons of Israel, saying, ‘In the seventh month on the first of the month you shall have a rest, a reminder by blowing of trumpets, a holy convocation.

You shall not do any laborious work, but you shall present an offering by fire to the Lord.’ ” The Day of Atonement

Then the Lord spoke to Moses, saying,

“On exactly 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 and present an offering by fire to the Lord.