I Samuel 24 Saul Caught With His Pants Down.

Saul is in pursuit of David to murder him and he walks into the very cave where David and his men were hiding. While Saul was taking a crap David cuts off a corner of his robe to show that if he wanted to, he could have killed Saul. In the end David left vengeance up to the LORD. “Therefore may the LORD be judge between you and me” (v. 15). David respected the office that Saul occupied but not necessarily the person in it. He knew Saul for the reprobate that he was. Saul asks David to swear that he would not cut off his descendants, but David was already in covenant with Jonathan, so even this request was narcissistic.