“And David said, “As the LORD lives, the LORD will strike him, or his day will come to die, or he will go down into battle and perish. The LORD forbid that I should put out my hand against the LORD’s anointed.” (1 Samuel 26:10–11 ESV)

David had an abiding faith in God’s sovereign providence over people and events.  God had promised that David would be king over Israel, but Saul was king and Saul wanted to kill David.  Why not take the opportunity to dispatch the sleeping Saul and claim the kingdom for himself?  Hadn’t God promised David the kingdom?

David doesn’t take the easy bait.  It was for the Lord to govern the affairs of Saul, not for David to take matters into his own hands. 

We could learn from David here.  We are often prone to force God’s hand in matters, or be impatient and not wait for God to move events but to manipulate them ourselves because we perceive the end as glorifying God, but forget that the means or timing might not be of God.