01. The Law
Saul was hunting David. In a cave, Saul entered unknowingly where David was hiding. It was the perfect chance. David could have killed the mad king. Instead, he cut the corner of Saul's robe... and even then, his conscience struck him.
02. The Mechanics
The mechanic of honor separates the Person from the Position. David didn't honor Saul's character (which was bad), but his anointing ("he is the Lord's anointed"). Touching authority touches God. Honor protects the giver more than the receiver.
03. The Application
It's easy to honor good leaders; the test is honoring difficult ones. Do you speak ill of those above you? David teaches us to leave judgment to God. "The Lord judge between me and you, but my hand shall not be against you." Honor the position; God handles the promotion.