Yu Yi is the son of Gong Xuan, that is, mourning for the public. Childe Feng is the son of Mu Gong, namely Zhuang Gong. He did not appoint his son and Yi, but his younger brother Mu Gonghe. When Mu Gong died, he did not appoint his son Feng, but his younger brother and son Yi. Both of them showed integrity.
His name is Jia, and he is his father's son. Later, Kong was named as the surname, that is, the Confucius family of Lu.