華嚴一乘教義分齊章 3.50

3.50

若三乘始教，法身是常，以自性故；亦無常，以離不離故。修生功德是無常，以從因緣生故、是有為無漏故；亦得是常，以無間斷故、相續起故。《莊嚴論》云「自性無間相續，三佛俱常住」等。

According to the initial teaching of the Three Vehicles: the dharmakāya is permanent because it is of its own nature; it is also impermanent because of separation and non-separation. Cultivated merit is impermanent because it arises from causes and conditions and is conditioned and taintless; it may also be permanent because it is uninterrupted and arises in succession. The Mahāyānasūtrālaṃkāra says: "Self-nature, uninterrupted, and continuous: the three buddhas are all permanently abiding," and so on.