成唯識論述記 7.237

7.237

述曰：第七、八識，行相恒內緣，一類沈審，起藉緣少，一切時有，以行相細，故無緣礙令總不行。總不行之言，謂第七識無漏、滅定，違染一分不行，非體總無也。又但可令轉變，非總不行，故與前別。以第六識麁動故，亦為緣礙，此即第一翻解常現起言，以八識相望，不同前五。復異後二名常現起，取次第二翻下文。云由斯頌中，不說此第六隨緣現，於此第一翻解末，亦應說之，彼雙結故。

The Commentary states: The modes of activity of the seventh and eighth consciousnesses constantly take internal objects, are uniform, deep, and reflective, rely on few conditions to arise, and are present at all times; because their modes of activity are subtle, there are no conditions that obstruct them so as to cause them not to operate entirely. The words “not to operate entirely” mean that in the undefiled state and the cessation attainment of the seventh consciousness, only the defiled portion does not operate, not that its substance is entirely absent. Furthermore, conditions can only cause them to undergo transformation, but not to cease operating entirely; hence they differ from the former [six]. Because the sixth consciousness is coarse and fluctuating, it is also obstructed by conditions. This is the first alternative explanation of the words “constantly manifests in active operation”: viewing the eight consciousnesses against one another, it is not like the first five, and also differs from the latter two, hence it is termed “constantly manifests in active operation.” Following this is the second alternative below. Because of this, it is not stated in the verse that this sixth consciousness “manifests according to conditions”; at the end of this first alternative explanation, this should also be stated, for that concludes both.