成唯識論述記 1.418

1.418

述曰：自下第三，以體例功能。量云：薩埵等三事體，應各有多；即是功能故；如彼功能。功能多者，一一上有多功能故，即生大等諸功能也。體唯各一，例能亦多，以能為量亦爾。就彼所執，故以為喻。

The Commentary states: Below is the third [refutation], taking the essence by analogy with the capacities. The syllogism is: The essences of the three entities, sattva and the rest, should each be multiple; because of being identical to their capacities; like those capacities. As for "capacities being multiple": upon each [entity] there are multiple capacities, which are the capacities to produce mahat and so forth. The essences are each only one; by analogy with the capacities, they should also be multiple; the syllogism taking the capacities [by analogy with the essence] is likewise. It is based on what they posit, hence it is used as an example.