Leviticus 16:29

The seventh month Answering part to our September and part to our October; when they had gathered in all their fruits, and were most at leisure for God's service. This time God chose for this and other feasts, herein graciously condescending to men's necessities and conveniences. This fast began in the evening of the ninth day, and continued till the evening of the tenth. Your souls Yourselves, both your bodies, by abstinence from food and other delights; and your minds, by grief for former sins, which, though bitter, yet is voluntary in all true penitents, who are therefore here said to afflict themselves, or to be active in the work.