1 Samuel 21

Fleeing for his life, David arrives at Nob, seeking help from the priest Ahimelech. David lies, claiming he is on a secret mission for Saul. David requests the sacred showbread (consecrated to God) to eat and takes Goliath's sword, which was kept in the sanctuary. David then flees to Gath, the Philistine city, but when recognized, he pretends to be insane to avoid capture, feigning madness by scribbling on the doors and letting saliva run down his beard.