David was in a place of being King, but not yet being King. He shares this trait with Joseph, if you remember. Joseph’s dreams telling him of the place of honor he would be in, however, having to wait for this to be realized. With David, it was clearer still. Samuel had anointed him King over Israel at a time when Saul was still king – and so David had to wait, had to careful, and had to scatter for safety’s sake before having others follow and gather around him in a move that would lead to the will of God being made known to the people of Israel, and the promise that David would be King being fulfilled.