In the traditional hierarchy of the five relationships in China, the emperor-subject relation ranks above the family relationship. Thus if one is given a surname by the emperor, it is an honor to accept it.
在中國人的五倫觀念裡，天地君親師，皇帝比自己的祖宗還要重要，因此當皇帝賜姓，就是無上的光榮。