俱舍論疏 1.232

1.232

論「除前及後至名為行蘊」，第三出行蘊體也。除前謂色、受、想，及後謂識蘊。餘有為法，簡無為也。即是除四蘊及無為，餘一切法皆行蘊攝。以法多故，從通立名。

On the passage in the treatise from "Excluding the preceding and subsequent" to "is called the volition skandha": Third is bringing out the intrinsic nature of the volition skandha. "Excluding the preceding" refers to form, feeling, and conception; "and subsequent" refers to the consciousness skandha. "Remaining conditioned phenomena" excludes the unconditioned. That is, excluding the four skandhas and the unconditioned, all remaining phenomena are subsumed under the volition skandha. Because the phenomena are numerous, the name is established from the general term.