It appears as if Saul had learned something of the loyalty pacts made between his son Jonathan and David.1 He probably assumed that their pact was common knowledge amongst his men and that their refusal to tell him was because of disloyalty on their part. Increasingly paranoid, he thus assumed that his men were in a conspiracy with David against him.2
8 that all of you have conspired against me? No one discloses to me when my son makes a covenant with the son of Jesse. None of you is sorry for me or discloses to me that my son has stirred up my servant against me, to lie in wait, as at this day.”