No leavened bread was to be eaten by the Hebrews for seven days in commemoration of their hasty escape from Egypt (see Exodus 12:17–20). In later biblical history, the Feast of Unleavened Bread is used in reference to the covenant obligation of purging corruption after celebrating redemption.
6 Et le quinzième jour de ce mois, ce sera la fête des pains sans levain en l'honneur de l'Eternel; vous mangerez pendant sept jours des pains sans levain.