Compared to this Eternal Buddha and His teaching preached in the essential section, those preached in the theoretical section, the pre-Lotus sūtras, the Sūtra of Infinite Meaning, and the Nirvana Sūtra, namely, all the sūtras preached prior to, at the same time as, and after the Lotus Sūtra, are easy to believe in and understand. It is because they are provisional teachings adjusted to meet the faith and comprehension of the unenlightened while what is preached in the essential section transcends them all and is difficult to believe in and comprehend because it adheres to the true intent of Śākyamuni Buddha.

Kanjin Honzon-shō, A Treatise Revealing the Spiritual Contemplation and the Most Verable One, Writings of Nichiren Shōnin, Doctrine 2, Page 152