The term “Honjinanjikyochi本地難思境智 (The inconcerivable state of the Original Buddha where Buddha wisdom and Dharma-kaya became one)” can be found in Volume 10 of Chang-an's “the Commentary on the Fahua wenchu.” The Original Buddha is revealed in 16 of the Lotus Sutra, in which the word means the Perfect Enlightenment that the Buddha acquired. The thought of the Original Enlightenment has developed in the Tendai sect of Japan.
The interpretation of the word by Nichiren is similar to the interpretation of Chang-an. However, Nichiren understood the Hommon Sections of the Lotus Sutra as the center of all Buddhist Texts. Therefore, he has come to realize “The inconcerivable state of the Original Buddha where Buddha wisdom and Dharma-kaya became one” as the Fundamental Truths of the Lotus Sutra.
In the history of the subsequent Nichiren religious group, the term was interpreted variously. The opinion influenced by the interpretation of Japanese Tendai sect is also in it.