大般涅槃經義記 2.221

2.221

第二迦葉就小徵問「二乘解脫若非是色，云何得住？」下佛答之。答意如何？彰彼二乘所得解脫亦色非色，以是色故二乘得住。於中先喻，中有二：一明非想亦色非色，佛說非色。四空有色，諸經大同，《華嚴》宣說菩薩鼻根聞無色界宮殿之香；《阿含經》中說舍利弗般涅槃時，色、無色天空中淚下如春細雨；波闍波提般涅槃時，色、無色天佛前側立，此云亦色與彼相似。二「如是」下就人正辯，是佛境界，非二乘知。下合顯法，「解脫亦爾，亦色非色，說為非色；亦想非想，說為非想」，合上初句。

Second, Kāśyapa interrogates in terms of the small: "If the liberation of the two vehicles is not form, how does it abide?" Below, the Buddha answers it. What is the intent of the answer? It reveals that the liberation attained by those of the two vehicles is also form and non-form; because it is form, the two vehicles can abide. Within this, there is first a metaphor, which has two parts: 1. Clarifying that neither-perception[-nor-non-perception] is also form and non-form, yet the Buddha spoke of it as non-form. That the four formless [realms] possess form is largely agreed upon across the sūtras: the Avataṃsaka explains that the bodhisattva's nose faculty smells the fragrance of palaces in the formless realm; in the Āgama sūtras it is said that when Śāriputra entered parinirvāṇa, the devas of the form and formless [realms] shed tears from the sky like fine spring rain; when Prajāpatī entered parinirvāṇa, the devas of the form and formless [realms] stood respectfully to the side before the Buddha. Saying here that it is "also form" is similar to those. 2. From "Thus" below directly explains in terms of the person: it is the Buddha's realm, not known to the two vehicles. Below, it combines and reveals the Dharma: "Liberation is also like this: it is also form and non-form, yet is spoken of as non-form; it is also perception and non-perception, yet is spoken of as non-perception," which matches the first clause above.