Saññā Sutta [SN 18.6, PTS 2.247]

6.

The Discourse on Perception

193. He was dwelling at Sāvatthī, etc. "What do you think, Rāhula, is perception of visible forms permanent or impermanent?" "Impermanent, venerable sir." Etc. "Perception of sounds... etc. Perception of odours... Perception of flavours... Perception of tangibles... Is perception of mental phenomena permanent or impermanent?" "Impermanent, venerable sir." Etc. "Seeing thus, Rāhula, a learned noble disciple becomes disenchanted with perception of visible forms, etc. He becomes disenchanted with perception of sounds... He becomes disenchanted with perception of odours... He becomes disenchanted with perception of flavours... He becomes disenchanted with perception of tangibles... He becomes disenchanted with perception of mental phenomena, etc. he understands." The sixth.