仁王護國般若波羅蜜多經疏 3.229

3.229

Question: Since the treatise states that one passes through three great kalpas, how much time does one great kalpa encompass? Answer: As the lower fascicle of the Yingluo Jing states: "Suppose there is a great stone eight hundred leagues square, and a cloth from the Śuddhāvāsa heaven brushes it once every three years; when this stone is brushed away entirely, it is called one asaṃkhyeya kalpa."