David had two separate opportunities to kill Saul. King Saul fully understood that David would someday replace him as King over Israel, and that his family would take a subordinate roll in affairs of state. As a result of this and the wretched sin of jealousy Saul had chased David throughout the countryside in an effort to kill David and to stop the plan of God. Even with all of this David felt it would be wrong to take Saul's life. He would wait on God and not curse himself by touching the Lord's anointed even though Saul was clearly a backslider.
In 2 Samuel 1 we read the story of the death of Saul. During the battle at Gilboa, Saul was wounded and left alive on the battlefield. An Amalekite happened upon Saul so Saul begged him to end his life so that the Philistines would not capture him alive. The Amalekite was very excited to tell David the good news. He took Saul's crown and his bracelet and found David at his home in Ziklag. However, David was less than thrilled with the man and he had him killed. "And David said unto him, How wast thou not afraid to stretch forth thine hand to destroy the LORD'S anointed? And David called one of the young men, and said, Go near, [and] fall upon him. And he smote him that he died." 2 Samuel 1:14-15
When we gossip and slander each other, are we not as guilty as the Amalekite? God has called us to love one another and to encourage one another. He has also called us to battle and crucify this old flesh through obedience to the Holy Spirit and the word. If we kill each other with our words, how will we reach the world around us. Are we not setting ourselves up for destruction? "But if ye bite and devour one another, take heed that ye be not consumed one of another." Galatians 5:15