These four great bodhisattvas neither presented themselves at the seat of enlightenment under the bodhi tree where Śākyamuni Buddha attained Buddhahood for the first time, nor rushed to the vicinity of the Hiraṇyavati River when the Buddha passed away. During the eight years when the Buddha preached the Lotus Sūtra on Mt. Sacred Eagle, moreover, they were neither among those holy people such as Bodhisattvas Mañjuśrī and Maitreya who assisted Him in preaching the preface and main discourse of the theoretical section, nor among such great bodhisattvas as Avalokiteśvara and Wonderful Voice who vowed to spread the sūtra after the death of the Buddha at the assembly in the epilogue of the essential section. Upholding solely this one great secret dharma, they retired to their true abode underground, not once reappearing in the world even after the death of the Buddha, for 2,000 years in the Ages of the True Dharma and Semblance Dharma. This was, after all, because the Buddha entrusted to them the propagation of this one great secret dharma solely in the Latter Age of Degeneration.

Soya Nyūdō-dono-gari Gosho, A Letter to Lay Priest Lord Soya, Writings of Nichiren Shōnin, Doctrine 3, Pages 160.