大乘起信論廣釋卷第三．四．五 3.56

3.56

Treatise: "What are the five? [...] because the unawakened mind is stirred." Commentary: Next is the differentiation and explanation below, specifically explaining the five manas, which is divided into five parts. This is the first.

"Named karmic consciousness" designates its name—that is, the first, the characteristic of karma, among the nine characteristics. Previously, relative to avidyā it was a characteristic, being the manifestation of the substance of avidyā; here, relative to the true mind, it is called consciousness. Relying on the mind, it is the manas that is relied upon; the consciousness forms the manas. The subsequent ones should be understood accordingly.
"The power of avidyā" adduces the condition relied upon, clarifying that the mind does not arise of itself, but when it arises it must have conditions.
"The unawakened mind is stirred" directly clarifies the meaning of karma, because the meaning of stirring into activity is the meaning of karma.