We have already seen on various occasions that the Priestly writer has a vested interest in genealogies, dates, and the ages of the patriarchs. But when this textual tradition with its dates and ages is redacted together with the JE text some interesting narrative tensions arise.
For instance, P informs us that Ishmael “was 13 years old when he was circumcised at the flesh of his foreskin” (17:25)—that is “on that very day” (17:23) when Abraham, who was himself 99 years old (17:24), received the covenant of circumcision from El Shaddai (17:1-14). At Genesis 21:3b-5, the next P text, we are informed that a year later Abraham is now 100 years old and Isaac is born. Therefore, according to this tradition Ishmael is 14 years old at Isaac’s birth.
Yet when this textual tradition (P) is placed before the Elohist’s version of Hagar’s expulsion in Genesis 21:6-21, inconsistencies in the narrative chronology of the now combined JEP text arise.
Following Genesis 21:3-5 above, which we have assigned to P, the text then continues:
5And Abraham was 100 years old when Isaac, his son, was born to him. [P]
6And Sarah said, “God has made laughter for me. Everyone who hears will rejoice for me.” 8And the boy grew and was weaned. And Abraham made a big feast in the day that Isaac was weaned. 9And Sarah saw the son of Hagar, the Egyptian, whom she had borne to Abraham, playing around. 10And she said to Abraham, “Cast out this maid and her son…” [E]
14And Abraham got up early in the morning and took bread and a bottle of water and he put them and the boy on Hagar’s shoulder, and he sent her off. And she went and strayed in the Beersheba wilderness. 15And the water was finished from the bottle, and she thrust the boy under one of the shrubs. . . 16and she said “Let me not see the boy’s death…” [E]
Although E’s version does not give us Ishmael’s age, there are nevertheless enough details in the narrative to deduce this. For we are told that Ishmael is small enough to be carried on Hagar’s back (from Gerar to Beersheba), that he still feeds from a bottle, and that he is small enough and helpless enough to be thrown under a shrub and left for dead. This tradition clearly depicts him as still a mere babe himself or a very young boy—certainly not a late teenager as in the Priestly tradition!
In other words, in the combined text as we now have it (JEP), and say we allow 1-3 years for the weaning of Isaac, Ishmael is 15-17 years old when he is cast out according to the Priestly tradition! But in the Elohist’s account of Ishmael’s expulsion, Ishmael is still a mere babe and could not have been 15-17 years old!
We will see other places where chronological inconsistencies or outright contradictions occur in the narrative due to a later editorial process that stitched together 2 different and variant textual traditions.