QUESTION: What does “send a messenger back” mean in this sūtra?

ANSWER: The messenger refers to the Four Reliances, four ranks of bodhisattva-teachers whom people turned to for guidance after the death of Śākyamuni Buddha. There are four kinds of messengers. First, are the bodhisattva-teachers of Hinayāna Buddhism. They would mostly appear in the first 500 years of the Age of the True Dharma. On the other hand, the second, the bodhisattva-teachers of Mahāyāna, for the most part would appear in the latter 500 years of the Age of the True Dharma. The third, bodhisattva-teachers of the theoretical section, would appear mostly in the 1,000-year Age of the Semblance Dharma and partly in the beginning of the Latter Age of Degeneration. The fourth, bodhisattva-teachers of the essential section, namely those numerous bodhisattvas who had appeared from underground, would surely appear in the beginning of the Latter Age.

The phrase, “send a messenger back,” in “The Life Span of the Buddha” chapter, which I have just cited, refers to those bodhisattvas who were called out from underground. “This excellent medicine” refers to Namu Myōhō Renge Kyō, which is the essence of the chapter, “The Life Span of the Buddha,” and which contains the five major principles: the name, entity, quality, function, and teaching of the Lotus Sūtra. The Buddha did not grant this excellent medicine to those bodhisattvas who had been guided by the teaching of the theoretical section, not to mention bodhisattvas from other worlds.

Kanjin Honzon-shō, A Treatise Revealing the Spiritual Contemplation and the Most Verable One, Writings of Nichiren Shōnin, Doctrine 2, Page 156-157