It is a Sabbath of complete rest to you, and you must afflict your souls. It is a statute forever. Bible

“It is a Sabbath of complete rest.” The Hebrew is shabbath shabbathon, more literally, “a Sabbath of Sabbath observance.” As any regular Sabbath, the affliction of the Day of Atonement was to last from sunset one day to sunset the next (cp. Lev. 23:32). [For more information on shabbath shabbathon, see commentary on Leviticus 25:4].

Commentary for: Leviticus 16:31