大般涅槃經疏 28.17

28.17

「我經中說一切眾生」下，第七爭論心常無常。薩婆多云：心無相續即是無常。僧祇云：心有相續即是常義。《成論》用薩婆提義，心有相續即是常也。文為二：先執心常、次執無常。初執常云：四大散壞是身破滅，作善業者心即上行即生好處，還將此心至於好處，豈非常義？作惡亦爾。

From "In my sūtras I say that all sentient beings" below, this is the seventh debate, on whether the mind is permanent or impermanent. The Sarvāstivādins say: the mind has no continuity, and thus is impermanent. The Mahāsāṃghikas say: the mind has continuity, which is the meaning of permanent. The *Tattvasiddhi-śāstra* adopts the Sarvāstivāda definition [of continuity as permanent]: because the mind has continuity, it is permanent. The text has two parts: first clinging to the mind as permanent, and next clinging to it as impermanent. The first, clinging to permanence, states: the four great elements scatter and disintegrate, and this body is destroyed; for one who performs wholesome karma, the mind then ascends and is born in a good realm; one takes this very mind back to the good realm—how is this not the meaning of permanence? The same holds for performing evil.