1 Samuel 26:9-12

9 But David said to Abishai, ‘Do not kill Saul. He is the man that the Lord has chosen to be Israel's king. Anyone who attacks him will be guilty of a sin. 10 I know that the Lord himself will kill Saul one day. Saul may die when he has reached the age to die. Or someone may kill him in a battle. He will certainly come to his end. 11 But I ask the Lord to stop me from hurting him, because he is the Lord's chosen king. Take the spear and the jar of water that are near Saul's head. We must leave here now!’

12 So David took the spear and the jar of water from beside Saul's head. Then they left. Nobody saw them. Nobody knew that they had been in the camp. Nobody woke up. Saul's soldiers continued to sleep because the Lord caused it to happen.