成唯識論述記 2.517

2.517

述曰：別破空多。汝今既說虛空體多，應非遍，非容受。色等中無故，非是遍；無色處有故，非容受，此即別破薩婆多等執有實無為者。此三無為雖復各有，破其一、多。毘婆沙師取空體一，餘二各多。此難雙關一、多並破。

The Commentary states: This specifically refutes the plurality of space. Now, since you say the substance of space is plural, it should be neither all-pervading nor receptive. Because it would not exist within form and the like, it would not be all-pervading; and because it would exist where there is no form, it would not be receptive. This specifically refutes the Sarvāstivādins and others who cling to real unconditioned phenomena. Although these three unconditioned phenomena each exist [for them], their oneness and plurality are refuted. The Vaibhāṣikas hold that the substance of space is one, while the other two are each plural. This refutation employs a double dilemma, refuting both oneness and plurality together.