... Saul went into a cave to relieve himself. But as it happened, David and his men were hiding farther back in that very cave!David C. McCasland writes that "there are times when it's best to wait for God to act instead of trying to make things happen ourselves. ... David knew that God had chosen him to become king. But he also knew that killing Saul was not the right way to make it happen. He would wait for God to remove Saul from the throne. ... Waiting for God to act is the best opportunity for the right things to happen His way."
“Now’s your opportunity!” David’s men whispered to him. “Today the Lord is telling you, ‘I will certainly put your enemy into your power, to do with as you wish.’” So David crept forward and cut off a piece of the hem of Saul’s robe. ... “The Lord forbid that I should do this to my lord the king and attack the Lord’s anointed one, for the Lord himself has chosen him.” So David restrained his men and did not let them kill Saul.
After Saul had left the cave and gone on his way, David came out and shouted after him, “My lord the king!” And when Saul looked around, David bowed low before him.
Then he shouted to Saul, “Why do you listen to the people who say I am trying to harm you? This very day you can see with your own eyes it isn’t true. For the Lord placed you at my mercy back there in the cave. Some of my men told me to kill you, but I spared you. For I said, ‘I will never harm the king—he is the Lord’s anointed one.’ Look, my father, at what I have in my hand. It is a piece of the hem of your robe! I cut it off, but I didn’t kill you. This proves that I am not trying to harm you and that I have not sinned against you, even though you have been hunting for me to kill me.
“May the Lord judge between us. Perhaps the Lord will punish you for what you are trying to do to me, but I will never harm you. As that old proverb says, ‘From evil people come evil deeds.’ So you can be sure I will never harm you. Who is the king of Israel trying to catch anyway? Should he spend his time chasing one who is as worthless as a dead dog or a single flea? May the Lord therefore judge which of us is right and punish the guilty one. He is my advocate, and he will rescue me from your power!” (New International Reader's Version)
As a control freak I tend to try to force things to happen the way I think they should, even if I need to manipulate people. This account of Saul and David is a reminder to me not to force my ways but to let things happen and wait on God.