From "Song Dynasty Ouyang Xiu, Song Qi·New Tang Book·Volume 110·Biography 22 Wei Zheng".

Original text:

If you use copper as a mirror, you can correct your clothes; if you use the past as a mirror, you can know the ups and downs; if you use people as a mirror, you can know the gains and losses. I try to protect these three principles and guard against my own mistakes. Now that Wei Zheng has passed away, Yi Jian has perished.

Translation:

Using copper as a mirror, you can organize a person's clothes; using history as a mirror, you can know the rise and fall of history; using others as your own mirror, you can Know your gains and losses every day. I often use this method to prevent myself from making mistakes, but now that Wei Zheng has passed away, I am missing a mirror.

Extended information

Background of this sentence

In the 17th year of Zhenguan (643), Wei Zheng died of illness. Li Shimin was very sad and abandoned the court for five days. Wei Zheng was posthumously given the title of Commander-in-Chief of Sikong and Xiangzhou, with the posthumous title of "Wenzhen". ?

After Wei Zheng's death, Li Shimin often said to the courtiers around him: "Use a bronze mirror to correct your clothes, use ancient history as a mirror to know the rise and fall, and use people as a mirror to see gains and losses clearly. . I often use this method to prevent myself from making mistakes, but now that Wei Zheng has passed away, I am missing a mirror.

After Wei Zheng passed away, I sent someone to his house and got a page of his suicide note, which I just drafted. The words are hard to read, only the first few lines are slightly legible.

It says: There is good and evil in the world. If good people are appointed, the country will be stable, and if evil people are appointed, the country will decline. Among the ministers, Emotions include love and hate. If you hate something, you will only see its evil. If you love something, you will only see its goodness. You should be careful between loving and hating. If you love and know its evil, hate and know its goodness, then get rid of it. If there is no hesitation in doing evil and no suspicion in appointing virtuous people, the country will prosper.

Baidu Encyclopedia—Learning from Copper

Baidu Encyclopedia—Wei Zheng