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 weaned (Gen 21:18 – according to Jewish rabbinical tradition, weaning occurs between 18 months and 5 years). At this time, Hagar and Ishmael are still living with Abraham and Sarah (Gen 21:19). Finally, Sarah demands that Hagar be sent away.
So Ishmael is at least fifteen years old when this happens. Definitely not a baby in arms. Did Hagar really carry a 15-year-old boy on her shoulder off into the desert? Did she really lay him down under a shrub to let him die?
Most scholars recognize that we have two independent stories here about Ishmael. If you’re familiar with the Documentary Hypothesis, it is the priestly source which reports that Ishmael grew into a teenager while still with Abraham. It is the Elohim source which reports that he was sent away with his mother, probably as an infant. These two contradictory traditions should not be read as a single story.