"There are other ladies in his court, 3,000 peerless beauties, who grind iron pestles into embroidery needles." What allusion comes from?

This should be a sentence used to tease others, which belongs to fiction. There is no such allusion in history. The first sentence comes from the Song of Eternal Sorrow: There are other women in his court, and 3,000 of them are stunning beauties, but his love for 3,000 is concentrated on one person. It is said that Yang Guifei is very loving. Li Bai was playful when he was a child. When he went to the river and saw an old lady grinding an iron pestle into an embroidery needle, it showed that he could succeed with his heart and persistence.

This ridicule says that people are too romantic and easy to hurt their bodies.

I have to say, the person who came up with this sentence is too arrogant.