It is stated in the Great Wisdom Discourse by Bodhisattva Nāgārjuna, “If this is so, isn’t it correct to say that the Flower Garland Sūtra and other Wisdom Sūtras are not the secret dharma, but that instead the Lotus Sūtra, which expounds the doctrine of attaining Buddhahood by the Two Vehicles, is the secret dharma? The Lotus Sūtra is like a great medicine master who can transform poison into medicine.” Commenting on this, Grand Master T’ien-t’ai states, “As a good physician can change poison into medicine, the Two Vehicles, who are considered incapable of attaining Buddhahood, were guaranteed by the Lotus Sūtra to become Buddhas in the future. This is indeed the transformation of poison into medicine. Therefore, it is stated in the Great Wisdom Discourse that no other sūtras but the Lotus Sūtra is the secret dharma.” The Great Concentration and Insight again states, “The Lotus Sūtra is called “myō (wonderful)” because it can remedy the mind of the Two Vehicles which no other sūtra can.” Grand Master Miao-lê says, “The Lotus Sūtra is said to be ‘myō’ as it can cure what is difficult to be cured.”

Ōta Nyūdō-dono Gohenji, A Reply to Lay Priest Lord Ōta, Writings of Nichiren Shōnin, Volume 6, Followers I, Page 33-34