It means: a gentleman doesn't need to have a full stomach, live comfortably, be diligent and agile, and speak cautiously, so he can find someone who has a good way to correct himself, so he can be said to be studious.

Excerpt from The Analects of Confucius VII

Excerpts from the original text:

Confucius said: "A gentleman does not want to eat enough, he is prepared for danger in times of peace and is sensitive to things, but he is cautious, honest and clean, which can be said to be studious."

Confucius said, "Eat less and drink more, bend your arms and pillow it, and have fun." Unjust wealth is like a cloud to me. "

Translation:

Confucius said: "A gentleman does not want to eat enough, live in peace, work hard and be careful in his words. In this way, they can be said to be studious. "

Confucius said, "I am very happy to eat coarse grains, drink cold water and bend my arms to make pillows." It's like a cloud to me to make myself rich and noble by improper means. "

Extended data:

The Analects of Confucius is a collection of quotations from Confucius and his disciples, which was compiled by Confucius' disciples and re-disciples until the early Warring States period. The book consists of 20 chapters and 492 sections, with quotations as the main part, supplemented by narration, which mainly records the words and deeds of Confucius and his disciples, and embodies Confucius' political opinions, ethical thoughts, moral concepts and educational principles. This book is one of the Confucian classics, and it is also called "Four Books" with Daxue, The Doctrine of the Mean and Mencius. Together with The Book of Songs, Shangshu, Book of Rites, Zhouyi and Chunqiu, they are called "Four Books and Five Classics".

The Analects of Confucius has three versions in ancient times, namely, ancient theory, Lu theory and Qi theory. The Analects of Confucius, which is popular now, is a version formed by collating Lu Lun and Gu Lun.

References:

The Analects of Confucius-Baidu Encyclopedia