Introduction to the courtyard wall of the outer courtyard: On the wall in the courtyard, there are many large-character slogans. Among them, there are inscriptions on the walls of the inner courtyard: "Youth is gone and never comes back, think about it carefully", "Recognize this here and now, don't be obsessed", "The maze is endless, turn back and find the right shore", "Tranquility and patience, no complaints or worries" and other words; on the wall of the outer courtyard are slogans such as "What the superior cannot see, think of, hear, and cannot do, we must see, think, hear, and do for the superior."