What is the origin of "Yi Jie Jin Lan" becoming sworn brothers?

Yi Jie Jin Lan means that like-minded friends make him a brother or sister of the opposite sex. The sources of words are as follows:

The meaning of this allusion is related to Jin Lan. This word comes from Shi Shuo Xin Yu: "On the one hand, it is similar to Ji and Ruan". Gong Shan, namely Dan Tao, was a famous scholar and politician in the Eastern Jin Dynasty and one of the seven sages of bamboo forest. His noble character was admired by later generations. It is said that he met Ji Kang and Ruan Ji one day and hit it off at once, thinking that they were bosom friends. Later generations used Cherokee Jin Lan to describe their relationship.

What are Jin Lan and Jin Lan? The language comes from "On the Cohesion of Yi": "If two people are United, their profits will be cut off; Words of one heart stink like moss. " Gold stands for hardness, odor stands for smell, and blue stands for fragrance. People use Jin Lan as a metaphor for friendship and profound friendship. You can use orchids to express your brothers' personality and mind when you become sworn. Orchids are as fragrant and pure as orchids. Similar words include "The Turn of Jin Lan", "Jin Lan" and "Jin Lan".

The Transformation of Jin Lan in History I. Yu Boya and Zhong Ziqi

In the Spring and Autumn Period, Yu Boya and Zhong Ziqi interpreted a story that bosom friends were hard to find. Yu Boya is good at playing and Zhong Ziqi is good at appreciating. After Zhong Ziqi's death, Yu Boya stopped playing the piano, thinking that no one in the world could appreciate his piano like Zhong Ziqi. I think the two of them are true bosom friends.

Second, Liu Bei, Guan Yu and Zhang Fei became sworn friends in Taoyuan.

When I think of Jin Lan, I will unconsciously think of the story of Liu Bei, Guan Yu and Zhang Fei who became sworn friends in Taoyuan. The three brothers became brothers when they were young, and then walked with each other, creating Shu Han in the Three Kingdoms period.