19 For seven days there must be no leaven found in your houses. If anyone eats something leavened, that person, whether a foreigner or native of the land, must be cut off from the congregation of Israel.
Exodus 12:19 Cross References - MSB
Exodus 12:15
15 For seven days you must eat unleavened bread. On the first day you are to remove the leaven from your houses. Whoever eats anything leavened from the first day through the seventh must be cut off from Israel.
Exodus 12:43
43 And the LORD said to Moses and Aaron, “This is the statute of the Passover: No foreigner is to eat of it.
Exodus 12:48
48 If a foreigner resides with you and wants to celebrate the LORD’s Passover, all the males in the household must be circumcised; then he may come near to celebrate it, and he shall be like a native of the land. But no uncircumcised man may eat of it.
Exodus 23:15
15 You are to keep the Feast of Unleavened Bread as I commanded you: At the appointed time in the month of Abib you are to eat unleavened bread for seven days, because that was the month you came out of Egypt. No one may appear before Me empty-handed.
Exodus 34:18
18 You are to keep the Feast of Unleavened Bread. For seven days at the appointed time in the month of Abib, you are to eat unleavened bread as I commanded you. For in the month of Abib you came out of Egypt.
Numbers 9:13
13 But if a man who is ceremonially clean and is not on a journey still fails to observe the Passover, he must be cut off from his people, because he did not present the LORD’s offering at its appointed time. That man will bear the consequences of his sin.
Deuteronomy 16:3
3 You must not eat leavened bread with it; for seven days you are to eat with it unleavened bread, the bread of affliction, because you left the land of Egypt in haste—so that you may remember for the rest of your life the day you left the land of Egypt.