Exodus 12:47-51

All the congregation of Israel are to celebrate this.

But if a stranger resides with you and celebrates the Passover to the Lord, all of his males are to be circumcised, and then he shall come near to celebrate it; and he shall be like a native of the land. But no uncircumcised male may eat it.

The same law shall apply to the native as to the stranger who resides among you.”

Then all the sons of Israel did so; they did just as the Lord had commanded Moses and Aaron.

And on that very day the Lord brought the sons of Israel out of the land of Egypt according to their multitudes.