I can’t recall where it was I read that mohammad said the numerous sects of the ‘religion’ he created would ultimately destroy each other.
From Anas that the Messenger of Allaah (sallallaahu ‘alayhi wa sallam) said:"The Children of Israa’eel divided into seventy-one sects and the Christians divided into seventy-two sects. And my Ummah shall divide into seventy-three sects, all of them being in the Fire except one sect."
[Related by al-Haakim in al-Mustadrak with the Talkhees of adh-Dhahabee (1/128), it is related in Majmoo‘ul Fataawaa (3/340) and (16/491) of Ibn Taymiyyah and ash-Shaatibee in al-I‘tisaam (2/189-191) and by al-‘Iraaqee in Takhreejul Ihyaa (3/230) and Ibn Hajar in Takhreej Ahaadeethul Kashaaf (p. 63). It was authenticated by Shaykh al-Albaanee in as-Saheehah (no. 203-204, 1492) and in Saheeh Sunan Ibn Maajah (no. 3225-3227) and in Dhilaalul Jannah (no. 63-67).]