Second Samuel opens with the account of a messenger coming to David and telling him that Saul and Jonathan and many others were dead.
Thinking to gain David's approval and possibly receive a reward from him, this messenger, who was an Amalekite, told David that it was at his hands Saul had died.
He said he had come upon Saul, who was still alive even after falling on his own sword. Saul had pleaded with him to kill him before the Philistines came upon him and mutilated his body while he was still alive.
The young man claimed he did as Saul requested. Some Bible students believe the young man told the truth; others believe he lied, but whatever the correct version is, he took his story to the wrong man.
David had always had a strong aversion to raising his hand against God's anointed. Neither would he permit any of his own men to do it. So when this young Amalekite claimed to have killed Saul, David had him put to death.
David did not want what the Lord did not give to him. He would not take by force what God had promised.
So many of us make the mistake of feeling we have to help God fulfill His promises.
"Thine, O Lord, is the greatness, and the power, and the glory, and the victory, and the majesty: for all that is in the heaven and in the earth is thine; thine is the kingdom, O Lord, and thou art exalted as head above all" (1 Chron. 29:11).