Parihānasutta
Ekaṁ samayaṁ āyasmā ca ānando āyasmā ca bhaddo pāṭaliputte viharanti kukkuṭārāme. Atha kho āyasmā bhaddo sāyanhasamayaṁ paṭisallānā vuṭṭhito yenāyasmā ānando tenupasaṅkami; upasaṅkamitvā āyasmatā ānandena saddhiṁ sammodi. Sammodanīyaṁ kathaṁ sāraṇīyaṁ vītisāretvā ekamantaṁ nisīdi. Ekamantaṁ nisinno kho āyasmā bhaddo āyasmantaṁ ānandaṁ etadavoca: “ko nu kho, āvuso ānanda, hetu, ko paccayo yena saddhammaparihānaṁ hoti? Ko nu kho, āvuso ānanda, hetu, ko paccayo yena saddhammaaparihānaṁ hotī”ti?
Decline
At one time the venerables Ānanda and Bhadda were staying near Pāṭaliputta, in the Chicken Monastery. Then in the late afternoon, Venerable Bhadda came out of retreat, went to Venerable Ānanda, and exchanged greetings with him. When the greetings and polite conversation were over, he sat down to one side and said to Ānanda: “What’s the cause, Reverend Ānanda, what’s the reason why the true teaching declines? And what’s the cause, what’s the reason why the true teaching doesn’t decline?”