Exo Exodus, chapter Book of Exodus, chapter 12
And when a stranger shall sojourn with youi, and will keep the Passover to the LORD-Yehōvah (Messiah Pre-Incarnate), 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.