大乘起信論義記 3.121

3.121

The phrase "from beginningless time... inconceivable activity" means that non-empty innate enlightenment is called untainted dharmas. Because this dharma secretly perfumes sentient beings and is not something that [ordinary] beings can comprehend, it is called "inconceivable activity." "Activity" here is the function of secret perfuming. "Acting as the nature of objective realms" explains that it does not merely perfume that deluded mind to make it feel revulsion and seek, thereby becoming the cognitive wisdom capable of contemplating, but it also serves as the contemplated objective realm for that contemplative wisdom. The phrase from "based on these two dharmas" onward reveals the function of perfuming. That is, because these two dharmas of mind and realm—or, these two dharmas of essence and mark—have power in secretly perfuming sentient beings, they cause them to give rise to practices such as revulsion and seeking. "Confidently believe..." and so forth explains the marks of giving rise to cultivation based on perfuming.