How did God's evident protection over Avraham and Yitzchak impact upon Avimelekh's attitude towards Yitzchak?
We read in Parashat Toledot of Yitzchak's tribulations in the Philistine region in Gerar, where his extraordinary farming success during a year of drought aroused the envy and then enmity of the local population. The Philistine king Avimelekh ultimately drove Yitzchak out of the region, due to the tension and hostility that had begun brewing in the kingdom. Later, however, Avimelekh and his general visited Yitzchak and asked for a truce, and explained their sudden change of heart: "We have indeed seen that the Lord was with you…" (26:28).
Rashi notes the seemingly redundant expression used by Avimelekh and his general in this verse – "ra'o ra'inu" ("we have indeed seen") – which suggests that they "saw" something in addition to the fact that "the Lord was with you." The subtle reference, Rashi explains, was to the success of Yitzchak's father. Avimelekh explains his shift in attitude on the basis of the fact that God's providence over both Avraham and Yitzchak was clearly evident, prompting him to seek peaceful relations with Yitzchak and his descendants.
The obvious question arises, how did the success and blessing enjoyed by Avraham decades earlier contribute to Avimelekh's change in policy towards Yitzchak? If Avraham's success was significant enough to impact upon Avimelekh's treatment of Yitzchak, he should never have driven Yitzchak away in the first place. How did God's evident protection over Avraham and Yitzchak impact upon Avimelekh's attitude towards Yitzchak?
Rav Dov Weinberger, in his Shemen Ha-tov (vol. 4), suggested that Avimelekh initially perceived Yitzchak as failing to perpetuate his father's legacy. Yitzchak's quality of gevura – unyielding justice – contrasted sharply with Avraham's attribute of chesed – his warm acceptance and kindness towards all human beings, deserving or otherwise. Yitzchak differed so fundamentally from his father that Avimelekh was unimpressed. Though he (or his father who bore the same title "Avimelekh") had suffered the consequences of mistreating Avraham, until he came to recognize his greatness, Avimelekh was not intimidated by Yitzchak. Ultimately, however, Avimelekh came to recognize that "the Lord was with you," that God came to Yitzchak's side and assisted him just as He had accompanied Avraham, and at that point Avimelekh acknowledged Yitzchak as Avraham's spiritual heir. Despite their differences in character and approach, both achieved spiritual greatness and earned special divine protection. It was at that point that Avimelekh chose to seek a truce with Yitzchak.
In a sense, this question surrounding Yitzchak's status underlies the entire narrative presented in this parasha regarding Avraham's wells. The Pelishtim had stuffed the wells dug by Avraham until Yitzchak's servants dug them anew, at which point the Pelishtim claimed rights to them. These quarrels over the wells of Avraham perhaps reflect the question over the continuation of Avraham's legacy. The Pelishtim argued that Avraham's spiritual legacy died with Avraham the person; the "waters" he had discovered through his teaching and influence can no longer continue, as Avraham had left no successor. The "stuffing" of the wells thus represents the rejection of Avraham's teachings.
Yitzchak had to struggle to prove that despite the differences between him and his father, he is legitimately the one to "dig anew" Avraham's "wells," that Avraham's legacy can and must be perpetuated even after his death, by his more reticent and rigid son. The story concludes with the Pelishtim's recognition of Yitzchak as Avraham's heir, that Avraham's legacy indeed continues with Yitzchak, and that the influence of a great, pioneering leader can be felt even many generations after the leader's passing, despite the differences between him and his successors.