大般涅槃經義記 9.243

9.243

「不從」已下是第二句以外類內，明外四大從緣集生，先無自性；內亦如是，何得先有？於中，為顯四大緣生，汎舉諸法類以顯之。「不從方便乳中得酪」簡酪異餘。謂不假於人工方便。「生蘇乃至一切諸法皆不如是非方便得」明餘異酪。「四大如是」明外四大類同諸法皆方便得。彼外四大從緣增長，先無自性；內亦如是，何得先有？

From "not from" onwards is the second phrase, using the external to analogize the internal, clarifying that the external four great elements are produced from an aggregation of conditions and have no prior self-nature; the internal is also like this—how could it exist previously? Therein, to show that the four great elements arise from conditions, it broadly raises various dharmas to show it by analogy: "Without relying on expedient means, curd is obtained from milk" distinguishes curd from other things—meaning it does not depend on human effort and expedient means. "Fresh butter and all other dharmas are not obtained without expedient means like this" clarifies that other things differ from curd. "The four great elements are also like this" clarifies that the external four great elements are like other dharmas in that they are all obtained through expedient means. Those external four great elements increase through conditions and have no prior self-nature; the internal is also like this—how could it exist previously?