Journey of the Path to Righteousness, p 51-52[During the Shodaiqyo ceremony w]hether ten, one hundred, or one thousand people chant together, they should chant collectively with “one voice” during Shodaigyo. Our hearts should ride upon this voice of Namu Myōhō Renge Kyō.
When you and Odaimoku become one, you may wonder, “Am I chanting? Or am I being chanted? Is the Odaimoku me? Or am I the Odaimoku?”
It becomes easy to fold and blend into the Odaimoku. Such is the condition of Shodai Zanmai “the Expanse of Shodai Boundlessness.”
At the stage of integration with our mind and the Odaimoku at that time our mind becomes Buddha mind. The state of chanting is the state of Buddha, the words of chanting are the words of Buddha, and the heart of chanting is the heart of Buddha. This state of becoming a Buddha is called Sokushin Jobutsu (becoming a Buddha in this very lifetime).
It is very difficult to remain in this state of Shodai Zanmai “the Expanse of Shodai Boundlessness.” In this state, one may perhaps only remain there for three to five minutes. During chanting, it is easy for the mind to stray. But rather than straying, we should eliminate straying and return to focusing on Shodaigyo. Doing so, we put ourselves again into Shodai Zanmai. If you are in Shodai Zanmai for just three or five minutes during a Shodaigyo session, the merits are huge.