1 Samuel 21:11-13

Young's Literal Translation

¹¹ and the servants of Achish say unto him, `Is not this David king of the land? is it not of this one they sing in dances, saying, `Saul smote among his thousands, and David among his myriads?'

¹² And David layeth these words in his heart, and is exceedingly afraid of the face of Achish king of Gath,

¹³ and changeth his behaviour before their eyes, and feigneth himself mad in their hand, and scribbleth on the doors of the gate, and letteth down his spittle unto his beard.