大乘起信論義記 3.388

3.388

諸佛如來離於見相無所不遍，心真實故，即是諸法之性。自體顯照一切妄法，有大智用無量方便，隨諸眾生所應得解，皆能開示種種法義，是故得名一切種智。

[The Śāstra says:] 'All Buddhas, Tathāgatas, are free from marks of perception and there is nowhere they do not pervade; because their minds are true and real, they are the very nature of all dharmas. Their own essence clearly illuminates all deluded dharmas, possessing great cognitive function and immeasurable skillful means; according to what sentient beings ought to understand, they can open up and reveal various teachings and meanings; therefore it is called the cognition of all modes.'