The original text is as follows:

A gentleman treats others with courtesy, and all men are brothers within the four seas.

Translation:

A gentleman is cautious and does not make mistakes; The attitude towards people is respectful and polite. Then there are brothers everywhere in the world, so why should a gentleman worry about not having brothers?

The Analects of Confucius:

The Analects of Confucius: A collection of recorded essays in China's Spring and Autumn Period, which mainly records the words and deeds of Confucius and his disciples. Reflects the thoughts of Confucius. It was compiled by Confucius disciples and re-disciples. The book, with 20 articles and 492 chapters, is the first "bibliography". In the Southern Song Dynasty, Zhu, Mencius, the University and the Doctrine of the Mean were called "Four Books".