He then required of Abraham and his seed circumcision, which was a circle cut in the flesh, as a token that God had cut them out and separated them from all nations as his peculiar treasure. By this sign they solemnly pledged themselves that they would not intermarry with other nations; for by so doing they would lose their reverence for God and his holy law, and would become like the idolatrous nations around them. (3SG 297.1) MC VC

By the act of circumcision they solemnly agreed to fulfill the conditions of the covenant made with Abraham on their part, to be separate from all nations, and be perfect. If the descendants of Abraham had kept separate from other nations, they would not have been seduced into idolatry. By keeping separate from other nations, a great temptation would be removed from them to engage in their sinful practices, and rebel against God. They lost in a great measure their peculiar, holy character, by mingling with the nations around them. To punish them the Lord brought a famine upon their land, which compelled them to go down into Egypt to preserve their lives. But God did not forsake them while they were in Egypt, because of his covenant with Abraham. He suffered them to be oppressed by the Egyptians, that they might turn to him in their distress, and choose his righteous and merciful government, and obey his requirements. (3SG 297.2) MC VC