Genesis 17:12

12 For the generations to come every male among you who is eight days old must be circumcised, including those born in your household or bought with money from a foreigner—those who are not your offspring.

Read Genesis 17:12 Using Other Translations

And he that is eight days old shall be circumcised among you, every man child in your generations, he that is born in the house, or bought with money of any stranger, which is not of thy seed.
He who is eight days old among you shall be circumcised. Every male throughout your generations, whether born in your house or bought with your money from any foreigner who is not of your offspring,
From generation to generation, every male child must be circumcised on the eighth day after his birth. This applies not only to members of your family but also to the servants born in your household and the foreign-born servants whom you have purchased.