俱舍論頌疏論本 13.31

13.31

第五法處色證者，又契經說：「苾芻當知：法謂外處，是十一處所不攝法，無見無對。」此經於法處中不言無色，故知法處中實有無表色。若無無表色，此經闕減，便成無用，謂經闕減無色言故。既不言無色，明知實有無表。

Fifth, as for the proof from forms in the dharmāyatana: furthermore, a sūtra states, "Bhikṣus, you should know: dharmas are the external āyatana, phenomena not subsumed by the eleven āyatanas, invisible and offering no resistance." This sūtra does not say there is no form within the dharmāyatana; therefore, one knows that within the dharmāyatana there is truly avijñapti-rūpa. If there were no avijñapti-rūpa, this sūtra would have an omission and become useless—namely, because the sūtra would omit the words "non-form". Since it does not say "non-form", one clearly knows that avijñapti is real.