This is the chapter in which God decides to change Abraham and Sarah’s names. I guess It didn’t like their old ones anymore. This is also the chapter in which God decides It really doesn’t like the foreskin and that all Its dolls needed to cut that icky bit of skin off from now on. So God again tells Abraham that his descendants will own all the land thereabouts, only this time in order to earn it, Abraham and all his men and all of their male descendants need to slice off that wee bit of skin. God also promises Abraham that Sarah will have a son that It will really really like, even though Sarah is going through menopause. Abraham’s rightly worried about his actual son Ishmael, but God blows him off with a promise that Ishmael would be blessed too.