1 Samuel 21:10-15

10And David arose, and fled that day for fear of Saul, and went to Achish the king of Gath. 11And the servants of Achish said to him, Is not this David the king of the land? did they not sing one to another of him in dances, saying, Saul hath slain his thousands, and David his ten thousands? 12And David laid up these words in his heart, and was greatly afraid of Achish the king of Gath. 13And he changed his behaviour before them, and pretended to be mad in their hands, and made marks on the doors of the gate, and let his spittle fall down upon his beard.1 14Then said Achish to his servants, Lo, ye see the man is mad: why then have ye brought him to me?2 15Have I need of mad men, that ye have brought this fellow to play the mad man in my presence? shall this fellow come into my house?