俱舍論疏 6.203

6.203

論「豈不亦說至為能作因」，有部類釋。經說能生是無常，不廢常法。是何緣經說無常為能生？豈廢不障為能作？

[When] the treatise [states]: "Does it not also say ... [is it not capable of acting as] an efficient cause (kāraṇahetu)?" the Vaibhāṣika explains by analogy: "The sūtra states that what can produce is impermanent, [yet] this does not exclude permanent phenomena. On what grounds does the sūtra's statement that the impermanent is what can produce exclude non-obstruction from being an efficient [cause]?"