金光明最勝王經疏 3.19

3.19

贊曰：下明應身。初明常、後明無常。此初常也，初牒身名、次顯應體。應身依法起，法是應本性，故從本性稱無始。故《攝大乘》云「所依常故，應化亦常。」故今所依無始，應身亦無始。若爾，化身亦應無始。答：應說不說，互相影顯故。若自受用，剎那相續；若他受用；此處滅餘處復續。

Commentary: Below explains the saṃbhogakāya. First permanence is explained, and afterwards impermanence. This is the first, permanence. It first cites the name of the body, and next reveals the essence of the saṃbhoga. The saṃbhogakāya arises relying on the Dharma; the Dharma is the original nature of the saṃbhoga, so from its original nature it is called beginningless. Thus the Mahāyānasaṃgraha says: 'Because its locus of reliance is permanent, the saṃbhoga and nirmāṇa are also permanent.' Therefore, since what it relies upon now is beginningless, the saṃbhogakāya is also beginningless. If so, the nirmāṇakāya should also be beginningless. Answer: What should be said and what is not said implicitly illuminate each other. For svasambhogakāya, it continues moment by moment; for parasambhogakāya, as it ceases here, it continues again elsewhere.