Exodus 12:44

When thou hast circumcised him. It was not through natural descent but by virtue of a divine call that Israel had become the people of the Lord. Being destined, in that capacity, to be a blessing to all nations, Israel was not to assume an exclusive attitude toward foreigners. They were to welcome those who desired to join them in the worship and service of God. Being incorporated politically and economically, these “strangers” were also to be accepted religiously through the rite of circumcision. Thus they became one with God’s people and were permitted to participate in the Passover ritual (see v. 48).