Iti 18
Itivuttaka: The Group of Ones
translated from the Pali by
Thanissaro Bhikkhu
This was said by the Blessed One, said by the Arahant, so I have heard: "One thing, when arising in the world, arises for the detriment of many, for the unhappiness of many, for the detriment & unhappiness of many beings, both human & divine. Which one thing? Schism in the Sangha. When the Sangha is split, there are arguments with one another, there is abuse of one another, ganging up on one another, abandoning of one another. Then those with little confidence [in the teaching] lose all confidence, while some of those who are confident become otherwise."
Doomed for an aeon to deprivation, to hell: one who has split the Sangha. Delighting in factions, unjudicious he's barred from safety from bondage. Having split a Sangha in concord, he cooks for an aeon in hell.