The Words and Phrases of the Lotus Sūtra, fascicle 10, says, “A question was asked why Never-Despising Bodhisattva was in such a hurry in preaching the Lotus Sūtra while the Buddha had not expounded it for 42 years after appearing in the world. It was answered that the Buddha preached the Hinayāna teaching first for the people who had possessed the seed of Buddhahood by listening to the Lotus Sūtra in the past life, whereas Never-Despising Bodhisattva sowed the seed of Buddhahood by preaching the true Mahāyanā teaching of the Lotus Sūtra for the people who had never heard of the sūtra in the past life.”
This interpretation by Grand Master T’ien-t’ai means that as we look at the past of those who listened to the pre-Lotus sūtras such as the Flower Garland Sūtra preached at the place of Enlightenment, the Āgama sūtras preached in the Deer Park, the Sūtra of the Great Assembly preached at the Daihōbō, and the Wisdom Sūtra preached by the White Heron Pond, including both the Hinayāna and Mahāyanā and provisional and true teachings as well as the four doctrinal teachings and the eight teachings (the four doctrinal teachings plus the four methods of teaching), they had received the pure and perfect seed of Buddhahood in the eternal past at the time of the Eternal Buddha and the Great Universal Wisdom Buddha. Nevertheless, because of their sin of slandering the One Vehicle teaching of the Lotus Sūtra, they have been unable to attain Enlightenment wandering instead around in the world of darkness for as long as “500 (million) dust-particle kalpa” and “3,000 dust-particle kalpa.” However, the seed they had received grew gradually until finally the time had come for them to hear the Lotus Sūtra on Mt. Sacred Eagle and to become aware of the gem (Buddhahood) given by the Buddha in the past. For 40 years or so till the Lotus Sūtra was preached, the Buddha preached the Hinayāna and provisional sūtras to them in order to prepare their capacity to understand as the Buddha thought that even those who had established a relationship with the Lotus Sūtra in a past life might speak ill of it for a variety of reasons.
Soya Nyūdō-dono-gari Gosho, A Letter to Lay Priest Lord Soya, Writings of Nichiren Shōnin, Doctrine 3, Pages 149-150.