Now all the people took note of it, and it pleased them, just as everything the king did pleased all the people. – 2 Samuel 3:36

David was an anointed and gifted leader of Israel and, as such, his decisions often revealed both a heart after God and a head with which to lead the people.
When David’s lead general officer (Joab) murdered Abner (Saul’s former commander), David had many reasons to rejoice. After all, Abner had led a rebellion against David’s reign. Instead, as king, King David publicly grieved. This sincere action proved to be wise in every respect. The other tribes of Israel respected Abner and would have been angered by the circumstances of his death. At a time when Israel needed to unify behind its new king, a critical and intense situation, David led masterfully.
Great leadership, in those times when people are looking for someone to lead, is not only seen in strength, but also in grace.
According to Scripture, virtually everything that truly qualifies a person for leadership is directly related to character. – John MacArthur