Exodus 12:43 KJV
And the Lord said unto Moses and Aaron, This is the ordinance of the passover: There shall no stranger eat thereof:
Exodus 12:43, King James Version
In context
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.