“ The Grand Progenitor said: “A man who serves his lord does not forget his origins, he is a just gentleman of the empire. When do you think he will leave?” Zhang Liao said: “Yu has received your benevolence. He will leave after he has repaid you.”
2 Your subject [Pei] Songzhi ( [裴] 松之) considers that Duke Cao knew that Yu was not going to stay, and admired his determination. By not sending someone in pursuit when Yu left, he confirmed his sense of righteousness. If he did not have the magnanimity of a hegemon, how could he accomplish this? Truly, this was the virtue of Duke Cao. ”

“ He is prominent man of our times, the like of Ying (英) [Zhang Ying] and Peng (彭) [Peng Yue] . He can contest victory with Yide (益德) [Zhang Fei] in combat but cannot better ‘the bearded’, who is unsurpassed among his fellows.” Yu had a magnificent beard, hence Liang referred to him as ‘the bearded’. After reading the letter, Yu was greatly pleased and displayed it to his retainers.
1 Shu ji: Earlier, when Liu Bei was at Xu, he went hunting with Duke Cao. During the chase, the hunting party dispersed and Guan Yu urged Bei to kill the Duke, but Bei refused. ”

“ Quan sent his generals to attack Yu, they captured Yu as well as his son Ping. Quan wanted to let Yu live to oppose Liu and Cao. His attendants said: ‘Don't rear a wolf cub, it will surely be of harm in the future. When Duke Cao did not eliminate him, he acquired for himself a great threat. ”