仁王護國般若波羅蜜多經疏 2.20

2.20

The commentary states: Proceeding from the coarse to the subtle, it clarifies emptiness step by step. All conditioned phenomena drift and gallop without abiding; the past is already non-existent, the future will be non-existent, and the present thought-moment must not be considered truly existent. Breaking down this single thought-moment, there are ninety kṣaṇas; do not consider a kṣaṇa to have a real substance. Breaking down a single kṣaṇa, there are nine hundred arisings and ceasings. Since a single kṣaṇa is constituted of many arisings and ceasings, the kṣaṇa is without substance; since a single thought-moment is composed of many kṣaṇas, the thought-moment is without real substance. Therefore, it is said that all phenomena are empty thought-moment by thought-moment.