1 Samuel 21:13-15

Darby Translation

¹³ And he changed his behaviour before them, and feigned himself mad in their hands, and scratched on the doors of the gate, and let his spittle fall down on his beard.

¹⁴ And Achish said to his servants, Behold, ye see the man is mad: why did ye bring him to me?

¹⁵ have I lack of madmen, that ye have brought this one to rave in my presence? shall this [man] come into my house?