起信論疏筆削記 6.37

6.37

是故不動下，二、結指。謂以隨熏動時，性未嘗變，故得生滅門中有真如也。故云：不動亦在動門。若真如門中則未必有生滅，生滅門中則必有真如，以生滅藉真如，真如不藉生滅故。略如前釋，廣在下文。是故下，指文。本覺者，即生滅門。初云：此識有二種義，能攝一切法，生一切法。云何為二？一者覺義、二者不覺義等。即彼覺義便是生滅門中真如，名為不動。但以至此門中別約形待義邊，易名為覺。上文等者，即立義分中云：是心生滅因緣相，能示摩訶衍自體相用故。彼之自體亦即生滅門中真如也。此上兩段正是動中有不動義。

[On] 'Therefore, the unmoved,' etc.: the second [part], concluding and pointing [to the text]. This means that when it moves in accordance with perfusion, its nature has never changed; therefore, within the aspect of arising and ceasing there is tathatā. Hence it says: 'The unmoved is also in the aspect of motion.' While in the aspect of tathatā there is not necessarily arising and ceasing, in the aspect of arising and ceasing there must be tathatā, because arising and ceasing rely on tathatā, whereas tathatā does not rely on arising and ceasing. This was briefly explained before and is treated in detail in the text below. [On] 'Therefore,' etc.: pointing to the text. 'Original enlightenment' refers to the beginning of the aspect of arising and ceasing, which says: 'This consciousness has two kinds of meaning, which can embrace all dharmas and produce all dharmas. What are the two? The first is the meaning of enlightenment; the second is the meaning of non-enlightenment,' and so forth. That very meaning of enlightenment is precisely the tathatā within the aspect of arising and ceasing, termed 'unmoved.' However, upon reaching this aspect, it is specifically spoken from the side of relative contrast, changing its name to 'enlightenment.' [On] 'The text above,' etc.: in the Section on Establishing the Meaning, it says: 'It is the marks of the causes and conditions of the arising and ceasing of this mind, because it can reveal the essence, attributes, and function of the Mahāyāna itself.' That very essence is also the tathatā within the aspect of arising and ceasing. These two passages above are precisely the meaning of the unmoved within motion.