Journey of the Path to Righteousness, p 42-44[During the Shodaigyo ceremony] our shin (mind/heart) is Ima Shinkyo No Gotoshi (wishing to be like a horse and having shin like a monkey).
Shin is like a wild, untamed horse. Such a wild horse runs freely with no concern; shin is not calm. We call this Ima (wishing to be like a horse), comparing shin to a wild horse.
Shin Kyo (having a mind/heart like a monkey) means that when a monkey is in a cage which has three windows, it looks out one window, in an instant it moves to another window, then another again, not sitting down for even a moment. In like manner, our shin cannot compose itself for even a moment just as a monkey keeps changing windows to look out of. So collectively, we call these Ima (wishing to be like a horse) Shin Kyo (having a mind/heart like a monkey). Shin is like this. However, with practicing Joshingyo … our shin becomes comfortable and calm. It is like the sediment of murky water sinking gradually to the bottom with the water becoming clean. So with our shin naturally becoming purified and tranquil. A state of shin like this is a “state of mind purification which is unlimited.”
Shin and body then align to become harmonious, stable, upright and uplifted. Even the physical body benefits, with improvements to the hormonal and circulatory systems. This is due to the autonomic nervous system becoming naturally balanced. Positive effects are garnered on health and longevity. Especially today, with people becoming overtly nervous and stressed, we should recognize the usefulness of this. …
When our shin becomes clear, we have good eyes to perceive things as they actually are. Doing so, we are able to take correct action. After practicing Joshingyo (usually five minutes to ten minutes or perhaps as long as thirty minutes to one hour, depending on time), shin becomes composed. We are now ready for chanting appreciative Odaimoku (our primary Buddhist practice). Now, we are able to chant good and steadfast Odaimoku.