大乘起信論裂網疏 5.101

5.101

問：虛空無邊故世界無邊，世界無邊故眾生無邊，眾生無邊故心行差別亦復無邊，如是境界無有齊限，難知難解。若無明斷，永無心相，云何能了一切種，成一切種智？答：一切妄境從本已來，理實唯一心為性，一切眾生執著妄境，不能得知一切諸法第一義性。諸佛如來無有執著，則能現見諸法實性而有大智，顯照一切染淨差別，以無量無邊善巧方便隨其所應，利樂眾生。是故（唯其）妄念心滅，（乃能）了一切種，成一切種智。

'Question: Because empty space is boundless, worlds are boundless; because worlds are boundless, sentient beings are boundless; because sentient beings are boundless, the distinctions in their mental activities are also boundless. Such realms are without limit and are difficult to know and difficult to comprehend. If ignorance is severed and there are forever no mental marks, how can one comprehend all aspects and accomplish the knowledge of all aspects? Answer: All delusive objects from the beginning are in principle and reality nothing other than the one mind as their nature. All sentient beings grasp at delusive objects and cannot come to know the supreme truth-nature of all phenomena. The Buddha-Tathāgatas are free from grasping; therefore they can directly perceive the true nature of phenomena and possess great wisdom that clearly illumines all defiled and pure distinctions, benefiting and gladdening sentient beings with immeasurable and boundless skillful expedients according to their needs. Therefore, (only when) the mind of false thoughts ceases (can one) comprehend all aspects and accomplish the knowledge of all aspects.'