1 Samuel 21:10-15

That day David ran away from Saul and went to Achish king of Gath. But the servants of Achish said to him, “This is David, the king of the Israelites. He’s the man they dance and sing about, saying: ‘Saul has killed thousands of his enemies, but David has killed tens of thousands.’ ” David paid attention to these words and was very much afraid of Achish king of Gath. So he pretended to be crazy in front of Achish and his servants. While he was with them, he acted like a madman and clawed on the doors of the gate and let spit run down his beard. Achish said to his servants, “Look at the man! He’s crazy! Why do you bring him to me? I have enough madmen. I don’t need you to bring him here to act like this in front of me! Don’t let him in my house!”