大方廣圓覺修多羅了義經略疏 1.822

1.822

然法門廣說無量無邊，今齊此結數者，對治塵勞故。塵勞即有八萬四千，一一對翻即皆淨法故，染與淨數無增減故。《論》云：「不覺念起，見諸境界，故說無明乃至具有過恒沙等妄染之義。對此義故心性無動，即有過恒沙等諸淨功德相義示現。」

Although Dharma doors are broadly spoken of as immeasurable and boundless, here the count is concluded at this number in order to counteract defilements. There are eighty-four thousand defilements; when each is individually overturned, they are all pure dharmas, so the numbers of defiled and pure neither increase nor decrease. The treatise says: 'Because thoughts arise through non-enlightenment, one sees the various realms; therefore avidyā is spoken of, up to possessing deluded defilements that exceed the sands of the Ganges. Countering this meaning, the nature of the mind is unmoving, which manifests all pure virtuous characteristics exceeding the sands of the Ganges.'