1 Samuel 21:13-15

And he changed his behaviour before them, and feigned himself mad in their hands, and scrabbled on the doors of the gate, and let his spittle fall down upon his beard. {scrabbled: or, made marks} Then said Achish unto his servants, Lo, ye see the man is mad: wherefore {then} have ye brought him to me? {is mad: or, playeth the mad man} Have 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?