Both Genesis 17:15-22 and Genesis 18:1-15 narrate the promise of Isaac’s birth, yet each one does so in drastically different manners. Let us first look at the version found in Genesis 18.
1And Yahweh appeared to him at the oaks of Mamre. And he was sitting at the tent entrance in the heat of the day, 2and he raised his eyes and saw, and here were three men standing over him… 8And he took curds and milk and the calf that he had prepared and placed them in front of them, and he was standing over them under the tree and they ate. 9And they said to him “Where is Sarah your wife?” And he said, “Here in the tent.” 10And he said, “I shall come back to you at the time of life and, behold, Sarah your wife will have a son.” (18:1-10)
Some of the features of this text, which we have also seen elsewhere, include this narrator’s use of the name Yahweh along with his anthropomorphic depiction of the deity. Of course later biblical traditions will suppress such anthropomorphism (see below), but this author apparently had no problems with it. Yahweh comes as a “man”; he walks, talks, and finally even eats with Abraham. It is probably safe to assume that narratively speaking Abraham doesn’t immediately recognize the “man” as Yahweh until later in the event (see v. 27). Furthermore, the whole episode is set in the typical ancient custom of giving hospitality to a stranger, and prompts the reciprocal gift given by Yahweh—the promise of the birth of Abraham’s heir, Isaac. Since this episode immediately follows Hagar’s expulsion we assume that this son, of whom the promise of Sarah’s future birth speaks, will inherit the covenant made to Abraham and his seed. Yet we should also note that the text leaves this implicit. This version was penned by the Yahwist.
We have discussed elsewhere how the later Priestly writer modified his Yahwist source by composing a whole new narrative (#24). If we ask why the Priestly writer felt obliged to craft a new and different story of Isaac’s birth, the response that we might receive is that here too the Priestly writer adds or emphasizes latent themes not explicitly stated in the Yahwist account, and places greater emphasis on theological tenets dear to himself or the priestly guild he represented.
First, Yahweh does not come to Abraham as a “man” nor in any manner for that matter. Rather he “appears” to Abraham and not as Yahweh (for Yahweh does not reveal himself in the Priestly text until Moses (#11)), but as El Shaddai. “And Abram was ninety and nine years old, and Yahweh appeared to Abram and said to him: ‘I am El Shaddai’” (17:1). Interest in dates is another characteristic feature of P. So basically in P’s modified version, Yahweh’s anthropomorphism is completely suppressed.
Second, the Priestly writer introduces the theme of a name change at this pinnacle point in the narrative (17:5). Only in P is there a name change from Abram to Abraham, Sarai to Sarah.1 In fact, this is the god’s first intervention with Abraham in the Priestly source.
Third, as we saw in P’s rewriting of the covenantal promise of the land (#28), here too the theme of an eternal covenant with Isaac is emphasized and brought to the fore. The Priestly writer also adds a blessing for Ishmael, namely that he too shall become the father of twelve tribes, and invokes the Priestly blessing “be fruitful and multiply” (17:20). The passage further specifies that whereas God blesses Ishmael, he nonetheless establishes his covenant with Isaac. This is made explicit here and clearer than it was presented in the Yahwist text.
And lastly the Priestly text narrates a scene completely absent in his Yahwist source, namely that of the circumcision of the whole household of Abraham, ratifying as it were, the covenant established between God and Abraham and his seed.
If the Priestly writer was indeed composing his text at a later period in time, to an exilic audience, and to address the concerns and needs of this community, and he envisioned the new narration as replacing the older Yahwist version, then it is only due to a literary irony that a later redactor sought to preserve them both, thus leaving behind the very contradictions that we have been examining.
- Friedman, The Bible with Sources Revealed, 56.↵