Exodus 12:45

42 It is a night to be much observed unto the LORD for bringing them out from the land of Egypt: this is that night of the LORD to be observed of all the children of Israel in their generations.

43 And the LORD said unto Moses and Aaron, This is the ordinance of the passover: There shall no stranger eat thereof:

44 But every man's servant that is bought for money, when thou hast circumcised him, then shall he eat thereof.

45 A foreigner and an hired servant shall not eat thereof.

46 In one house shall it be eaten; thou shalt not carry forth ought of the flesh abroad out of the house; neither shall ye break a bone thereof.

47 All the congregation of Israel shall keep it.

48 And when a stranger shall sojourn with thee, and will keep the passover to the LORD, let all his males be circumcised, and then let him come near and keep it; and he shall be as one that is born in the land: for no uncircumcised person shall eat thereof.