Exodus 12:48-50

New Revised Standard Version, Anglicised

⁴⁸ If an alien who resides with you wants to celebrate the passover to the Lord, all his males shall be circumcised; then he may draw near to celebrate it; he shall be regarded as a native of the land. But no uncircumcised person shall eat of it; ⁴⁹ there shall be one law for the native and for the alien who resides among you.

⁵⁰ All the Israelites did just as the Lord had commanded Moses and Aaron.