Who does calligrapher Su Kuang refer to?

Calligrapher Su Kuang refers to Huai Su.

Huai Su, a calligrapher in the Tang Dynasty, is famous for "Weeds" and is known as "the sage of grass" in history. The common surname is money, and the word hides the truth. He is from Lingling, Yongzhou. Huai Su, a monk, enjoys calligraphy in his spare time after meditation, and is as famous as Zhang Xu. The artistic features of Huai Su's calligraphy are: the pen is powerful and the wrist rotates like a ring. Free and unrestrained, fluent can be called one go.

The story of Huai Su.

Huai Su was very interested in Buddhism since he was a child. At the age of ten, he decided to become a monk. After becoming a monk, he not only studied Buddhism, but also became interested in calligraphy. In order to improve his calligraphy level, he traveled around, learned from the calligraphers at that time, and devoted himself to studying the inscriptions of ancient calligraphers, copying them humbly. However, due to poor family, I can't afford to buy paper to practice calligraphy, so I have to try my best to practice calligraphy. This is the inspirational story of practicing calligraphy with banana leaves that has been passed down through the ages.