十不二門指要鈔 2.64

2.64

初、約性德直示者，迷悟緣起皆三千之體起於妙用，體既不出剎那，妙用豈應離體？故使緣起咸趣剎那。三千既其不變，剎那之性本常，以體收用緣起理一，不分而分十界百界，約十界則六穢四淨，約百界則十通淨穢，十中一一各六四故。

First, directly pointing [to this] in terms of inherent virtues: the conditioned arising of both delusion and awakening is the substance of the three thousand realms giving rise to wondrous function. Since the substance does not fall outside of a single thought-moment, how could the wondrous function be separated from the substance? Therefore, it causes all conditioned arising to converge into a single thought-moment. Since the three thousand realms do not change, the nature of a single thought-moment is fundamentally permanent. Subsuming function within substance, the principle of conditioned arising is one; without dividing, it divides into the ten realms and the hundred realms. In terms of the ten realms, there are six impure and four pure; in terms of the hundred realms, all ten pervade purity and impurity, because within each of the ten there are respectively six and four.