King Saul was so impressed with the "stripling" or adolescent David that he asked his army captain Abner to check him out. It's not every day nor every century nor millennium that someone slays a giant with just a sling and five stones.
The king was perceptive. This kind of prowess must come from the parent. The power underneath young David's skin comes not from his line of ancestry, but from his divine ancestry -- his Father God whom his earthly father Jesse had raised him to trust. As evident in David's audacious declaration of his confidence in God, "The Lord that delivered me out of the paw of the lion, and out of the paw of the bear, He will deliver me out of the hand of this Philistine."
King Saul was so captivated by young David that he kept him to serve him both within the comfortable confines of his palace and the fierce battlefront. The Bible says that David continued to do well in Saul's company. "And David went out whithersoever Saul sent him and behaved himself wisely; and Saul set him over the men of war, and he was accepted in the sight of all the people, and also over the men of war, and also in the sight of Saul's servants." David's seeming overnight celebrity provoked King Saul's jealousy. It was obvious to the king that the Lord was with David.
A celebrity status can last as long as the grandeur lasts, but it takes wisdom and favour for a celebrity to perpetuate that status. David rose from a shepherd boy, to become the sweet psalmist and king of Israel and Judah. In fact, David's name became eponymous. Consider key emblems in the Bible named after David -- the Key of David, the Root of David, the City of David, the Tabernacle of David, and most significantly, the Son of David [our Saviour and Lord Jesus Christ]. But more than being eponymous, David's name is synonymous with the phrase "the man after God's own heart", despite his checkered past. I believe there is a place where one can reach God intimately. Right in His heart.
"And the king said, Enquire thou whose son the stripling is." 1 Samuel 17:56 KJV