成唯識論述記 4.974

4.974

述曰：此依第八，如六十三說第七為意識，正與此同。八若無時七亦無故，《瑜伽》論說由有本識故有末那等。又無性言：本識是共依，故知此所依。

The Commentary states: This [consciousness] relies on the eighth. As fascicle sixty-three [of the Yogācārabhūmi] refers to the seventh as the mental consciousness (manas), this exactly agrees with it. This is because if the eighth is absent, the seventh is also absent; as the Yogācārabhūmi states, 'Because the basic consciousness exists, the manas exists,' and so forth. Furthermore, Asvabhāva states: 'The basic consciousness is the common basis'; therefore, one knows this is its basis.