What is "a friendship between gentlemen is as light as water"?

The phrase "The friendship between gentlemen is as light as water" comes from Zhuangzi Sanmu: "The friendship between gentlemen is as light as water, and the friendship between villains is as sweet as water; A gentleman is indifferent to his relatives, and a villain is willing to rest. "

This sentence means that a friendship between gentlemen based on morality is elegant and pure, as light as water. A gentleman, in ancient times, refers to a person with both ability and political integrity and high moral character, and is also called a gentleman with good moral character. A gentleman is magnanimous in nature, does not need to be on guard, pays attention to too much etiquette and humility, and can get along easily and calmly.

This sentence comes from an allusion: when Xue was poor, he got help from the Wang couple. Later, when he reached the top, Wang gave him two jars of clear water. Xue refused to accept the wine and gifts, but he just accepted the Qingshui King. Because he knows that the king is poor, it is also a beautiful thing to send clean water. This is a friendship between gentlemen as light as water.