'Day of Atonement' in the Bible

Also on the tenth day of this seventh month there shall be a day of atonement: it shall be a holy convocation unto you; and you shall humble yourselves, and offer an offering made by fire unto the LORD.

And you 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.

Then shall you cause the trumpet of the jubilee to sound on the tenth day of the seventh month, on the day of atonement shall you make the trumpet sound throughout all your land.