[I]t is stated in the Annotations on the Great Concentration and Insight that the book of the Great Concentration and Insight explains the way of practicing meditation based on the principle of the Lotus Sūtra and that the pre-Lotus, provisional sūtras are expedient means in preparation for preaching the True Dharma of the Lotus Sūtra. It means that the whole of the Great Concentration and Insight is based on the doctrine of “replacing provisional teachings with the true teaching” of the Lotus Sūtra. Therefore, although the Great Concentration and Insight quotes the pre-Lotus sūtras and non-Buddhist writings, it does not accept what is preached in them; it just borrows their sentences without meanings.

Jisshō-shō, A Treatise on the Ten Chapters of the Great Concentration and Insight, Writings of Nichiren Shōnin, Doctrine 2, Page 3