大般涅槃經義記 7.349

7.349

第二喻中，「空名無法、無法名空」牒前法說，「譬如世間無物名空」舉喻類顯，世間太虛是其本來自體無物，與彼法性理空相似故舉類之，「虛空之性亦如是」等辯法同喻。

In the second, metaphorical explanation: "Emptiness is called the absence of dharmas, and the absence of dharmas is called emptiness" takes up the earlier doctrinal exposition. "Just as in the world, the absence of things is called empty" provides an analogy to illustrate by comparison: the space of the world is originally, in its intrinsic nature, without things, and because it is similar to the principle of emptiness of that dharmatā, it is cited to compare with it. "The nature of space is also like this," and so forth, explains the congruence of the dharma with the analogy.