Emperor Taizong once stopped under a tree and said, "This is really a good tree." Yu and hurriedly followed and praised the tree. Emperor Taizong said seriously, "Duke Wei often advised me to stay away from villains. I don't know who the villain is, but I doubt you know either. " At first glance today, you really are. "Yu apologized to him and said," hundreds of officials of Chang 'an imperial court often fight opposite each other in the imperial court, so that your majesty has no chance to speak. Fortunately, only the minister is here today. If I don't obey your wishes at all, what's the point of your majesty being the son of heaven? " Emperor Taizong turned anger into joy.