Genesis 17:25, How Old was Ishmael when Abraham Sent Him Away? Part II of II

And Ishmael his son was thirteen years old, when he was circumcised in the flesh of his foreskin.

//Yesterday, I provided verses that make it sound like Ishmael was an infant when Abraham sent him and his mother Hagar away into the desert. But if we back up four chapters to today’s verse, we read that Ishmael was 13 when he was circumcised. Sometime afterward, another son, Isaac, is conceived. We can figure that nine months after that, Isaac is born. At least 18 months after that, Isaac is wea...