"Outside the mind there is no law; the sight of blue mountains fills the eyes," is one of the most well known of Zen sayings. The manner in which the universe is perceived is created by one's mind; there are no abstract set of laws that exist separately from the heart of our own existence. That existence is based on the experience of actual things. "Eyes filled with blue mountains" means "The reality (and beauty) of Buddha-nature is all around us. There is no need to construct an elaborate edifice of rules and regulations." Gesshu is one of the great calligraphers of the Soto Zen School. Although this piece has certainly experienced the ravages of time, the brushwork retains its impressive power and dynamic expression. Some of Gesshu's scrolls are in even worse shape: there is a Gesshu scroll that was half-burned away in fire. The remaining half was remounted and is now displayed as a temple treasure.
Gesshu was long-time abbot of Daijo-ji, an important Soto Zen temple in the Kaga District of northern Japan. Gesshu studied with the Obaku master Ingen, and we can see the influence of Obaku-styke calligraphy in his brushwork. Gesshu is one of the most important and influential masters of the Soto Zen school, and he is also held in high regard as a Zen calligrapher.