Isaac reopened the wells that Abraham had dug but the native inhabitants had later filled with earth. He also dug three new wells. In contrast with Abraham, Isaac "was called not so much to pioneer as to consolidate." [1][source]
This incident shows God"s blessing of Isaac, too. Water in the wilderness is a strong symbol of God"s supernatural blessing in spite of nature. [source][source][source]
The incident also reveals the peaceful character of this patriarch who did not battle his neighbors for the wells, even though he was stronger than they ( Genesis 26:16). His actions expressed his trust in Yahweh. [2][source]
Isaac"s decision to sojourn in Gerar and the territory of the Philistines ( Genesis 26:1-22) seems to have been unwise but not sinful. Though he sinned in misrepresenting his relationship to Rebekah out of fear ( Genesis 26:7), his choice to live in Gerar was not sinful. It did, however, open him to temptation and trials that he probably would have avoided if he had stayed away from Gerar. [source][source][source]