1 Samuel 21:13

His behaviour; his speech and gesture; and, it may be, his habit also. Feigned himself mad; which they might the more easily believe, partly because of the disappointment of his great hopes, and his extreme danger and trouble from Saul, which might well make him mad; and partly because he had put himself into their hands, which they supposed none but a fool or a madman would have done. And David counterfeited this madness, that he might procure both their pity and their contempt; that they being freed from jealousies and fears of future mischief from David, and from his wise conduct, of which they had sad experience, might be secure of him, and so spare him. In their hands, i.e. whilst he was in their power, and before them.