仁王經疏 3.161

3.161

問曰：四靜慮及無色界亦有淨法，如何說為不淨邪？解云：不淨自有多種。如《瑜伽》第二十六卷說，有六種不淨：一朽穢不淨，自有二種：一依內不淨，謂髮毛等；二依外不淨，謂青瘀等。二者苦惱不淨，謂苦觸所生受。三下劣不淨，所謂欲界。四觀待不淨，如待無色勝清淨事，色界諸法便似不淨；待菩迦耶寂滅涅槃，乃至有頂皆似不淨。五煩惱不淨，謂三界中所有一切結縛睡眠隨煩惱纏。六違壞不淨，謂五取蘊，無常無恒、不可保信、變壞法性，具說如彼。由此靜慮無色，皆名不淨。

Question: The four dhyānas and the formless realm also have pure dharmas; how can they be said to be impure? Solution: Impurity itself has many kinds. As stated in the twenty-sixth fascicle of the Yogācārabhūmi, there are six kinds of impurity: 1. Impurity of putrid filth, which itself has two kinds: (i) internal impurity, meaning hair, body hair, and so forth; (ii) external impurity, meaning blue-bruised corpses and so forth. 2. Impurity of suffering and affliction, meaning feelings born of painful contact. 3. Inferior impurity, namely the desire realm. 4. Correlative impurity: just as, when compared to the superior purity of the formless realm, the dharmas of the form realm seem impure; and when compared to the quiescence of nirvāṇa of the buddha-kāya, everything up to the peak of existence seems impure. 5. Impurity of afflictions, meaning all the fetters, torpors, and secondary afflictions throughout the three realms. 6. Impurity of destruction, meaning that the five appropriation aggregates are impermanent, non-eternal, unreliable, and of the nature of change and decay, as fully explained there. Because of this, both the dhyānas and the formless realm are called impure.