19 To this God said: “Your wife Sarah will definitely bear you a son, and you must name him Isaac.*+ And I will establish my covenant with him for an everlasting covenant to his offspring* after him.+

16 Now the promises were spoken to Abraham and to his offspring.*+ It does not say, “and to your descendants,”* in the sense of many. Rather, it says, “and to your offspring,”* in the sense of one, who is Christ.+