大乘起信論義疏 1.75

1.75

問曰：六識盡在初地，初地以上使無六識。云何得知見聞覺耶？答曰：雖無事相，六識猶有，七識緣照無漏所得法身，及與真識緣起法身眼耳等識，是故用此見聞覺也。

Question: The six consciousnesses are exhausted at the first bhūmi, so that above the first bhūmi there are no six consciousnesses. How does one know seeing, hearing, and perceiving? Answer: Although there are no phenomenal marks, the six consciousnesses still exist: the seventh consciousness's conditioned illumination of the dharmakāya attained through the undefiled, together with the eye, ear, and other consciousnesses of the dharmakāya as the conditioned arising of true consciousness; therefore these are used for seeing, hearing, and perceiving.