Elie sees the rabbi’s son run away from his father, and he wonders if he will have the strength to not do the same.
When the rabbi asks Elie where his son is, saying they got separated and he'd searched for his son’s remains among the bodies and dug through the snow for him, Elie does not know where the son is. Then he remembers that he saw the son running. He realizes he might have been running away from his father on purpose.
He had felt his father growing weaker and, believing that the end was near, had thought by this separation to free himself of a burden that could diminish his own chance for survival. (Section 5)
Elie finds himself sympathizing with the son, even though he loves his own father and has done everything he can to stay with him. He prays that he will have the strength to not do the same thing.
As he continues his experience, he sees the worst of human nature. To him, a son betraying his father is the ultimate sin. Yet he still worries that he might show the same weakness, and leave his father in order to save himself. He would hate himself for doing that, but he can imagine it happening.