Exodus 12:43-51

And the LORD said to Moses and Aaron, “This is the statute of the Passover: no foreigner shall eat of it, but every slave that is bought for money may eat of it after you have circumcised him. No foreigner or hired worker may eat of it. It shall be eaten in one house; you shall not take any of the flesh outside the house, and you shall not break any of its bones. All the congregation of Israel shall keep it. If a stranger shall sojourn with you and would keep the Passover to the LORD, let all his males be circumcised. Then he may come near and keep it; he shall be as a native of the land. But no uncircumcised person shall eat of it. There shall be one law for the native and for the stranger who sojourns among you.” All the people of Israel did just as the LORD commanded Moses and Aaron. And on that very day the LORD brought the people of Israel out of the land of Egypt by their hosts.