A wanderer who visited Samiddhi at the Vejuvana in Rājagaha and said that he had heard the Buddha declare that all action and speech were vain, and that what passed in the mind was the only thing of importance. A stage could be reached in which there was no feeling whatever. Samiddhi protested that Potaliputta misinterpreted the Buddha’s teaching, and Potaliputta then asked him questions regarding experience, which Samiddhi answered. Potaliputta, showing neither approval nor disapproval, walked away. When the Buddha heard from Ānanda of Potaliputta’s questions and Samiddhi’s answers he blamed Samiddhi for his hasty reply.
For details see Mahākammavibhaṅga Sutta. MN.iii.207ff.