Where it appears

• Exod 12:15“‘Seven days you shall eat unleavened bread; even the first day you shall put away yeast out of your houses, for whoever eats leavened bread from the first day until the seventh day, that soul shall be cut off from Israel.
• Exod 12:19There shall be no yeast found in your houses for seven days, for whoever eats that which is leavened, that soul shall be cut off from the congregation of Israel, whether he is a foreigner, or one who is born in the land.
• Exod 13:7Unleavened bread shall be eaten throughout the seven days; and no leavened bread shall be seen with you. No yeast shall be seen with you, within all your borders.
• Lev 2:11“‘No meal offering, which you shall offer to Yahweh, shall be made with yeast; for you shall burn no yeast, nor any honey, as an offering made by fire to Yahweh.
• Deut 16:4No yeast shall be seen with you in all your borders seven days; neither shall any of the meat, which you sacrifice the first day at evening, remain all night until the morning.