Commentary for Genesis 26:21

שטנה old French nuisement; English hindrance.

ויחפרו...שטנה, from the word “Satan.” The name reflected the fact that every time they dug with success they would be subjected to this hatred.

ויקרא שמה שטנה, “he called its name Sitnah. (hatred, enmity) He had given the Philistines the benefit of the doubt regarding denying his claim to the first well his servants had dug. But now he knew that that had not been mere coincidence, but a display of their hatred of him.

ויקרא שמה שטנה, “he named that well: “hatred.” We must not understand the name of this well as reflecting the same sentiments as the previous well he had dug, as at that time the name עשק, “dispute,” reflected that he gave the Philistines the benefit of the doubt when they claimed that the waters that came out of that well had previously flowed in their river. When they disputed his right to the second well, he became convinced that their arguments were malicious and not based on a legitimate claim.