With Ānanda (1st)Paṭhamaānandasutta

Then Venerable Ānanda went up to the Buddha, bowed, sat down to one side, and said to him:Atha kho āyasmā ānando yena bhagavā tenupasaṅkami; upasaṅkamitvā bhagavantaṁ abhivādetvā ekamantaṁ nisīdi. Ekamantaṁ nisinno kho āyasmā ānando bhagavantaṁ etadavoca:

“Sir, they speak of ‘schism in the Saṅgha’.“‘saṅghabhedo saṅghabhedo’ti, bhante, vuccati. How is schism in the Saṅgha defined?”Kittāvatā nu kho, bhante, saṅgho bhinno hotī”ti?

“Ānanda, it’s when a mendicant explains what is not the teaching as the teaching …“Idhānanda, bhikkhū adhammaṁ dhammoti dīpenti, dhammaṁ adhammoti dīpenti, avinayaṁ vinayoti dīpenti …pe… and what was prescribed by the Realized One as not prescribed by the Realized One.paññattaṁ tathāgatena apaññattaṁ tathāgatenāti dīpenti. On these ten grounds they split off and go their own way. They perform legal acts autonomously and recite the monastic code autonomously.Te imehi dasahi vatthūhi avakassanti apakassanti āveni kammāni karonti āveni pātimokkhaṁ uddisanti. That is how schism in the Saṅgha is defined.”Ettāvatā kho, ānanda, saṅgho bhinno hotī”ti.

“But sir, what does someone who has split a harmonious Saṅgha brim with?”“Samaggaṁ pana, bhante, saṅghaṁ bhinditvā kiṁ so pasavatī”ti?

“They brim with sin that lasts for an eon.”“Kappaṭṭhikaṁ, ānanda, kibbisaṁ pasavatī”ti.

“But sir, what is the sin that lasts for an eon?”“Kiṁ pana, bhante, kappaṭṭhikaṁ kibbisan”ti?

“They burn in hell for an eon, Ānanda.“Kappaṁ, ānanda, nirayamhi paccatīti—

A schismatic remains for the eonĀpāyiko nerayiko, in a place of loss, in hell.Kappaṭṭho saṅghabhedako; Taking a stand against the teaching,Vaggarato adhammaṭṭho, favoring factions, they ruin their sanctuary.Yogakkhemā padhaṁsati; After causing schism in a harmonious Saṅgha,Saṅghaṁ samaggaṁ bhinditvā, they burn in hell for an eon.”Kappaṁ nirayamhi paccatī”ti.