1 Samuel 31:1

Now the Philistines fought against Israel That is, gave them battle. As they began the quarrel, (1 Samuel 29:1,) so they seem to have begun the fight. It must be observed that the foregoing chapter is a digression, to relate what happened to David at this time. The sacred writer now resumes the thread of the narrative in regard to Saul, relating what befell him upon his return from Endor. And it seems he was scarce returned before the Philistines attacked his camp, and, after some resistance, broke into it. Delaney thinks that they were encouraged to this attempt by some secret information of Saul's having stolen out of the camp the evening before, with his general, Abner, (who is supposed to have been one of his attendants,) and another person. Certainly intelligence of that kind could not be hard to be obtained, and, if obtained, would be a strong encouragement to such an attack. And if this were the case, Saul's applying to the enchantress was the immediate cause of his destruction. See 1 Chronicles 10:13, where one cause of his death is stated to be his applying for counsel to one who had a familiar spirit.