金光明經文句記 4.122

4.122

二、「心常」下，明識常在。根塵即對即覺者，對塵便覺也。引《釋論》證即覺義。既云心欲聞，則知識在根。經「隨行」，平聲。

Second, below the words "the mind is constantly," explaining that consciousness is constantly present. That faculty and object immediately encounter each other and there is immediately awareness means that when facing an object one becomes aware immediately. Citing the Commentary (Da zhidu lun) to verify the meaning of immediate awareness: since it says "the mind desires to hear," one knows that consciousness resides in the faculty. In the sūtra, "following practice" is pronounced in the level tone.