Genesis 17:12-13 Every male throughout your generations, whether born in your house or bought with your money from any foreigner who is not of your offspring, both he who is born in your house and he who is bought with your money, shall surely be circumcised.

Why does God command Abraham to do perform circumcisions? This seems especially unjust towards an adult slave who apparently must relinquish themselves to genital alteration in addition to a general lack of physical freedom. Why doesn't God discourage Abraham from owning slaves in the first place?