瑜伽師地論略纂 3.57

3.57

七、作受解脫難中，「設是我者，我應無常」者，彼受者、作者等，不是諸行，即是我者，我應無常，有作用故，如手足等。「若無變異，應非受者」等，無變異故，如虛空等。

In the seventh challenge concerning the agent, the experiencer, and liberation, regarding "If it were the self, the self should be impermanent": if that experiencer, agent, and so forth are not conditioned factors, but are rather the self, then the self should be impermanent, because it has functional activity, like hands, feet, and so on. Regarding "If it is devoid of alteration, it should not be an experiencer" and so forth: because it is devoid of alteration, like empty space and so on.