roundness inside but squareness outside

roundness inside but squareness outside

It's also a square outside and a round inside. It is said to be upright in appearance and smooth in heart. According to the biography of Zhi Yun in the book of the later Han Dynasty, "the case is characterized by being greedy and evil, being a member of the foreign party and an insider, being a traitor of the clique and harming others." Li Xianzhu: "the speech is extended to show the square and straight on the outside, but on the inside, it is soft and weak. Confucius said: "the color is fierce, but the inside is easy."