In chapter 27 of the Romance of the Three Kingdoms, Guan Yu leaves Cao Cao to return to his old lord, Liu Bei. He seals up the gold that Cao Cao has given him and hangs up his seal of office, feng jin gua yin (封金挂印). One of Cao Cao’s generals wants to pursue him. Cao Cao stops him: “He does not forget his old lord. He comes and goes openly. He is a true man.”
Cao Cao then tells Zhang Liao: “Wealth could not move his heart. Rank and salary could not change his will. I respect such a man deeply.” He says that he will see Guan Yu off with travel money and a robe.