The original text is from Lv Xiang's Book of the New Tang Dynasty: "There is nothing in the world, and it is annoying for mediocrity."

Later generations changed it and it became like this.

It means it's nothing, just asking for trouble.

Besides, it doesn't come from any poetry.

This is just a word handed down by Sancan, the third ancestor of China Zen. But in ancient times, this sentence was regarded as a classic, so it was extracted from a large number of articles.