It is narrated from Hazrat Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: The Children of Israel were divided into seventy-one sects, of which seventy were destroyed and only one was saved. Whereas my Ummah will be divided into seventy-two sects, of which seventy-one will be destroyed and only one sect will be saved. The Companions (may Allah be pleased with them) asked, "O Messenger of Allah (peace and blessings be upon him)! Which is that one sect?" The Prophet (peace and blessings be upon him) replied: The one which adheres to the congregation.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 12479
Hadith Gradingحکم دارالسلام:صحيح بشواهده، وهذا إسناد ضعيف لضعف ابن لهيعة، ورواية سعيد بن أبى هلال عن أنس مرسلة