This week’s alumni Dvar Torah is by Elliot Dine.
By the end of his life, Avraham is the paragon of faith, the man willing to follow God to the end of Earth, to submit himself fully to God’s will. But in this week’s parashah, Avraham expresses exasperation towards God and demonstrates a striking lack of belief in G-d’s promises. Should we model our faith only after Avraham at the destination of his life’s journey, or are his stops on the way worthy of emulation as well?
In 13:6, God promises Avraham that “his progeny will be like the dust of the Earth” (13:6). The next time God promises to protect and reward him, Avraham states his skepticism about these promises, and he repeats his challenge — that he does not have anyone who will inherit — before letting God respond (15: 1-3). When God repeats his promise that Avraham’s progeny will be numerous, Avraham seems to believe Him (15:6), yet only two verses later Avraham exclaims “How do I know that I shall inherit it?!” (15:8). What explains Avraham’s initial disbelief? Why does he demand a sign that God’s promise will come true even after apparently regaining trust in Him?
The Ran quoted in the Abrarbanel provides an insightful answer to these question based on his close read of the text. Picking up on God’s promise of a “great reward”, Abraham challenges Him at first hinting and then stating outright that a great reward does him no good if he has no offspring he can leave the reward to. Furthermore, Abraham cannot believe that he will have offspring to give over all his wealth since he and Sarah are already well past the age of child-bearing. Thus, God assures Abraham that he will in fact have offspring; that the reward and protection that Abraham receives will continue on to the next generation. Yet, Abraham remains unsatisfied; he needs to know if he will see his children inherit the land. He still feels uneasy due to his old age and knows he cannot assure his children’s proper inheritance of the land. Therefore, God makes a new covenant with Abraham where he specifies how and when Abraham’s offspring will inherit. In sum, Abarabanel argues that Abraham in naturally fearing for his legacy and for his offspring’s well-being charges God to make new and to make good on his promises. 
It is only once God does so, once God makes this covenant that Abraham can have complete faith. The covenant made here allows Abraham to accept the challenges that lie ahead, to sacrifice the only offspring who will inherit him, for he now has God’s promise that his offspring will inherit the land only after 430 years. This episode illustrates that for Abraham, and consequently for us, in some cases it remains an appropriate response to challenge G-d’s action even when our concern is personal and not universal.
Abarbanel commentary on Genesis, 15:1 question 3
והר”ן הרגיש בספק הזה וכתב שבמאמר הראשון השיב לענין השכר שלא היה צריך לו יותר רכוש כיון שהיה ערירי בלא בנים. ובמאמר השני התלונן שבמאמר האלהי הנזכר שנאמר לו לא באה הבטחת הזרע בהיותו יותר צריך אליו מהרכוש ולהיותם שני ענינים באו עליהם שתי אמירות
The Abarbanel himself does not like this answer because it does not explain the separation between Abraham’s asking for a heir, believing in G-d’s promise and then asking for a sign later. I am less worried about this issue because in both cases it is G-d who starts the conversation, and the conversation appears to be about two different issues. The first deals with having an heir to inherit all the “reward” Abraham receives, while the second deals with Abraham’s descendants inheriting the land specifically.
Elliot Dine (SBM 2010,2015) is currently pursuing a PhD in molecular biology at Princeton University.