2

Ramban mentions this Rashi and says: And Rashi wrote, "He entered into it unto the place of Shechem to pray for the sons of Yaakov, when they would come from the field anguished. And this is correct. And I [would] add that Avraham held this place first, and before He gave him the land - it was [thus] hinted to him from this that his children would ...


1

It would seem that his tefillah was to change the outcome of the war (i.e., without it, Yaakov's sons might have fared badly). In a similar vein, also about Avraham's prayers - this time "between Beis-El and Ai" - the Gemara (Sanhedrin 44b) tells us that had it not been for that prayer, the (first) battle of the Jewish people against Ai (Joshua 7) ...


Only top voted, non community-wiki answers of a minimum length are eligible