法華玄贊義決 1.40

1.40

Fourth, because [the Buddha] wished to teach the dharma gates of the three purifications. The original nature of sentient beings is neither defiled nor pure; because of sentient beings' inversions, defilement and purity are formed. Because heavy defilements cannot be eradicated all at once, the buddhas and bodhisattvas gradually draw them out so as to open the three purifications: 1. Purifying the three wretched destinies with the five precepts and ten virtues; 2. Preaching the two vehicles to purify the triple realm; 3. Subsequently illuminating the One Vehicle to purify the three vehicles. Considering the three wretched destinies as severe suffering, the triple realm as middling suffering, and the death of inconceivable transformation as minor suffering, the three purifications were taught.