"Bing Xin Yu Hu Soul and Brush Teacher" comes from which article?

From Xunzi's article "Persuade Learning".

From: Xun Zi's Persuasion in the Warring States Period.

Original text:

The jade pot has a heart of ice, and the brush writes the soul of the teacher.

Translation:

The jade pot holds the teacher's blood, and the red pen writes the teacher's soul.

Extended data:

Creative background:

During the Warring States period, slavery further collapsed, the feudal system gradually formed, and epoch-making changes took place in history. Many thinkers expressed their opinions on the social changes at that time from different positions and angles, and gradually formed different factions such as Mohism, Confucianism, Taoism and Legalism, which was called "a hundred schools of thought contend" in history.

A hundred schools of thought contend and wrote many books, publicizing their own views and criticizing others, resulting in a situation of "a hundred schools of thought contend". Xunzi was a representative figure of Confucianism in the late Warring States period. He believes that the existence of nature does not depend on human will, but people can use subjective efforts to understand it, adapt to it and use it. In order to reveal the significance of learning the day after tomorrow, he created the article "Encouraging Learning".