大般涅槃經義記 1.229

1.229

第三純陀領解之中，「如是如是，誠如尊教」，總述佛語。如佛所說一切皆是，故曰如是。下別對之，「雖知如來方便涅槃，而我不能不懷苦惱」，對佛後勸不應啼泣，顯悲難止。「覆自思」下，對佛前答明己歡喜，由佛示滅，知有為過、趣入無為，所以歡喜。

In the third [part], Cunda's grasp and understanding: "So it is, so it is; it is truly as the Honoured One teaches" summarizes and confirms the Buddha's words. As everything the Buddha said is correct, he therefore says 'so it is'. Below, he responds to them individually: "Although I know the Tathāgata enters the nirvāṇa of expedient means, yet I cannot help but harbor distress" responds to the Buddha's subsequent advice that he should not weep, revealing that his grief is difficult to stop. From "reflecting further..." downward, in response to the Buddha's previous answer, he explains his own joy: because the Buddha demonstrates extinction, he knows the faults of the conditioned and enters the unconditioned, which is why he rejoices.