Dasan did not limit his teachings on being careful when alone to the concepts of space and time.
It is natural for a person who practices mindfulness to be tidy when alone. Rather, it is recommended that you reflect on whether you have done any harm or evil while interacting with others because they were unaware of it.
(…) Those in power at the time, who were busy with factional strife and vicious power struggles, eventually pushed Dasan out through exile.
They secretly hoped that Dasan would collapse from exhaustion from his long exile, but Dasan maintained his steadfastness throughout the difficult 18 years of exile.
And he completed the “Yeoyudangjeonseo” which consists of about 500 volumes.
A person of integrity will not break down under any circumstances.
--- From Chapter 1, “The Being I Respect Most Is Myself”

The stories Dasan left behind are a great inspiration to all book lovers.
“If you can carry a cartload of books in addition to your bedding and clothes, this is the conduct of an upright scholar.” This saying, recorded in the “Mokminsimseo,” talks about the desirable attire that one should have when first appointed as a local official.
He also sent letters to his children while in exile, urging them not to neglect reading books.
“There is only one way to behave well as a member of the clan: reading.
“If a child of the fallen family does not read and does not conduct himself properly, how can he be considered a human being?” “The only thing I pray and wish for day and night is that my second child will study hard.
“Please read diligently from early morning until late at night, and do not abandon this father’s earnest wish.” “If you truly do not want to read, the books I have written will be useless.
If my book is useless, I will be a useless person.
“Your reading is saving my life.” The two sons, Jeong Hak-yeon and Jeong Hak-yu, who were disciplined by their father’s earnest letter, were able to break free from the limitations of a fallen family and open their own paths as poets and government officials.

--- From "Chapter 2: People Grow as They Turn Their Heads"

Jasan and Shindoga, who were both prime ministers of the Jeong Dynasty, studied under Baekhonmuin, a teacher of the time.
Jasan, who was ashamed to study with Shindoga, who had his legs amputated as punishment, asks Shindoga to leave, criticizing him for thinking of studying with someone of such high status as himself when he is disabled.
Then the believer said:
“Many people will excuse themselves and say that they should not have been punished by having their feet cut off, but few will excuse themselves and say that they should not have had feet in the first place.
Only a virtuous person can realize that punishment is beyond human control, accept it as fate, and find peace of mind.
When a master archer shoots an arrow, if you are within that range, you are bound to get hit by the arrow.
If it doesn't fit, you're in luck.
(…) I have been with the Master for 19 years, but I did not know that I had no legs.
“You and I are in a relationship of heart, but you are only looking for me in appearance. How is that not wrong?” Hearing this, Jasan straightened his posture and said.
“Please, stop.”
--- From Chapter 3, “You must realize yourself to love yourself”

Lu Meng of Wu during the Three Kingdoms period of China was a general with sufficient qualifications, but his only flaw was his lack of scholarship.
Sun Quan, the emperor of Wu, told Lu Meng, who said he had no time to read, that he too was constantly reading books, and that “Emperor Guangwu of the Later Han Dynasty never let go of a book even on the battlefield at the border, and Cao Cao of Wei enjoyed learning even in his old age.”
Yeomong, who was greatly enlightened by the emperor's advice, always kept books close by and studied diligently even on the battlefield, thereby surprising Grand Admiral Lu Su, who usually looked down on him.
When Lu Su was discussing countermeasures against Guan Yu, the famous general of Shu, in the military camp, he was shocked to hear Lu Meng's five countermeasures.
Nosuk said to Yeomong, “I used to look down on you because you only had martial arts and military strategy, but now you have great learning, so you are not the Yeomong you used to be.”
To that, Yeomong replied, “A scholar should rub his eyes and look at each other again after three days of separation.”
After that, Yeomong became a brave warrior and a wise general, and succeeded Lu Su as the Grand Admiral of Wu.

--- From Chapter 4, “Study as if you were engraving it on your body and sharpening your mind”

Guan Zhong and Po Suk-ah are friends who grew up together and cared for each other since childhood.
They did business together and went to battle together, but each time, the crowd showed a cowardly side.
When Guan Zhong took more profit each time they did business together, Po Suk-ah would say, “Guan Zhong is poor, so it is natural for him to take more.”
When Guan Zhong fled several times on the battlefield, Po Suk-ah defended him, saying, “Guan Zhong is not a coward. It is natural for him to be cautious because he has to take care of his old mother.”
The highlight of their relationship was when they took different sides and fought against each other during a civil war in their country.
Guan Zhong sided with Gong Zi Gui, and Po Shuya sided with So Baek. When So Baek won, Guan Zhong was in danger of being executed.
However, Posuk-ah recommends Guan Zhong as a prime minister to So-baek and says this.
“If Your Majesty is satisfied with the king of my country, you may make me your prime minister.
But if you want to become the king of the world, make Guan Zhong your prime minister.” Guan Zhong said this about his friendship with Bao Shuya, who had saved him from death and recommended him as the prime minister of his state.
“My parents gave birth to me, but it was my father who understood me.”
--- From "Chapter 6: Be Lonely Until You Miss Yourself"

The life in exile, where he was rejected by everyone, must have been the loneliest and most difficult time in Dasan's life.
But at that moment, Dasan suddenly realized his calling.
“At this time, he quietly rejoiced, saying, ‘I have found leisure.’ He took with him three volumes of the “Sasangrye” and one volume of “Sangbok,” including annotations, and studied and investigated them meticulously, forgetting even sleep and eating.” Here, we can see when a person realizes the destiny of heaven.
Destiny comes like a flash in the loneliest and most difficult moments.
Once you realize your destiny, you must act immediately.
At that moment, Dasan began writing the first volume of the “Yeoyudangjeonseo,” researching it meticulously and completing it.
And I was happy to see the finished book.
It was precisely because of this attitude that Dasan was able to complete over 500 volumes of works.

--- From Chapter 7, “I Hear the Path I Must Take from the Heart That Has Passed”