The sentence "A gentleman must be careful about his independence" comes from "The University·Chapter 7".

Original text:

Those who are sincere in their intentions should not deceive themselves. Like hating bad odors, like loving lust, this is called self-effacement. Therefore, a gentleman must be careful about his independence. It is not good for a villain to live idle and do everything. When he sees a gentleman, he becomes disgusted and hides his bad deeds while focusing on his good deeds.

It is of no use to people who regard themselves as if their lungs and liver are weak. This means that sincerity is in the middle and appearance is in the outer, so a gentleman must be careful about his independence.

Zengzi said: "What the ten eyes look at and what the ten hands point to are so severe!" A rich house, a nourishing body with virtue, a broad mind and a fat body, so a gentleman must be sincere in his intentions.

Translation:

Making your thoughts sincere means not to deceive yourself. Just like you hate the smell of rancidity, just like you love beautiful women, everything comes from the heart. Therefore, a person of high moral character must be cautious even when he is alone. People with low moral character do all kinds of evil in private. When they see people with high moral character, they hide away, cover up the bad things they have done and brag about themselves.

As everyone knows, others can see you as clearly as your heart, lungs, and liver. What’s the use of covering it up? This is called the inner truth that will definitely show up on the outside. Therefore, a person of high moral character must be cautious even when he is alone.

Zengzi said: "Many pairs of eyes are looking at it, and many hands are pointing at it. Isn't this terrifying?!" Wealth can decorate a house, but character can cultivate the body and mind, making the mind broad and the body comfortable and healthy. . Therefore, a person of high moral character must make his thoughts sincere.