Xin Pi
When the Shu general Jiang Wei heard that Xin Pi was in Sima Yi's camp, he told Zhuge Liang, "Xin Pi has come with the imperial sceptre. The enemy won't come out of their camp (to attack us)." Zhuge Liang replied, "Sima Yi doesn't want to engage us in battle in the first place. His true intention in seeking permission from his emperor to attack us is, in fact, to show his troops that he is eager to fight and to keep them battle-ready. A general away on the battlefield doesn't necessarily need to follow his lord's orders. If (Sima Yi) can defeat us, why does he still need to ask for permission from his emperor, who is thousands of "li" away (from here)?"