9 Abraham, you and all future members of your family must promise to obey me. 10-11 As the sign that you are keeping this promise, you must circumcise every man and boy in your family. 12-13 From now on, your family must circumcise every baby boy when he is eight days old. You must even circumcise any man or boy you have as a slave, both those born in your homes and those you buy from foreigners. This will be a sign that my promise to you will last forever. 14 Any man who isn't circumcised hasn't kept his promise to me and cannot be one of my people.