4. Wŏnhyo’s discussion is based on Pusa jie ben(On Conferring Bodhisattva Precepts, T 1501.24.1110–1115). This text contains excerpts from the Yogācārabhumis´astra. Even though the Essentials can be categorized as a commentary in its style, in this work Wonhyo does not offer line-by-line comments on Pusa jie ben, which he mentions only rarely. Instead, he develops his own arguments on the nature of bodhisattva precepts and of observing and violating them.