Genesis 34:14-17

and said unto them, We cannot do this thing, to give our sister to one that is uncircumcised; for that were a reproach unto us. Only on this condition will we consent unto you: if ye will be as we are, that every male of you be circumcised; then will we give our daughters unto you, and we will take your daughters to us, and we will dwell with you, and we will become one people. But if ye will not hearken unto us, to be circumcised; then will we take our daughter, and we will be gone.