Genesis 21:26 - Ellicott's Commentary On The Whole Bible

I wot not. — This explains the reason of Abimelech’s visit. The king’s herdsmen had robbed Abraham of a well, a species of property jealously defended in the East because of its great value, and Abraham in some way had made his displeasure felt. Abimelech, ever friendly towards Abraham, by whose nobleness of character he had been greatly impressed, comes to learn the cause of the coolness, and to enter into a more close and lasting alliance with the patriarch. With Oriental indirectness, he makes no complaint, and speaks only of his wish for continued friendship, but by his allusion to his past kindness hints that this had not been received as it ought. Abraham fully understands his real meaning, and tells him what had happened; whereupon the matter is set right, and Abraham requites his previous generosity with gifts of cattle.