The Messenger of Allaah said,"What happened to the Children of lsraa'eel will happen with my Ummah, just as one shoe resembles the other, to the point that if one of them had intercourse with his mother openly, there would be someone who did that in my Ummah. The Children of Israa'eel split into seventy two sects and my Ummah will split into seventy three sects, all of which are in the Fire except one sect." They asked, "Which is that one, 0 Messenger of Allaah?" He replied, "That which I and my Companions are upon." Declared hasan by Shaikh al-Albaanee.
Allaah's Messenger said,"Stick to my Sunnah and the Sunnah of the rightly guided Caliphs after me, cling to that with your molar teeth and beware of new matters, for every innovation is misguidance." Reported by Ahmad, Abu Daawood (Eng. trans. 3/1294/no.4590), at-Tirmidhee (no. 2676), Ibn Maajah (no. 42), ad-Daarimee (no. 96) and Ibn Abee 'Aasim in as-Sunnah (no. 54). Shaikh al-Albaanee declares, "Its isnaad is saheeh, its narrators reliable."
Imâm At-Tirmidhî said:
"And the explanation of the jamâ`ah according to the people of knowledge is that it is the people of fiqh, knowledge and hadîth...
"...[`Alee bin Al-Husayn said:] I asked `Abdullâh bin Al-Mubârak, who is the Jamâ`ah? So he said, 'Abû Bakr and `Umar.' It was said to him, 'Indeed Abû Bakr and `Umar have died.' He said, 'So and so and so and so.' It was said, 'Indeed, so and so and so and so have died.' So `Abdullâh bin Al-Mubârak said, 'Abû Hamzah As-Sukkarî is the Jamâ`ah.'
"Abu `Îsa said said: And Abû Hamzah was Muhmmad bin Maymûn. And he was a righteous Shaykh, and he said this during our lifetime."
Shaykh Al-Albânî said:
"This is supported by the statement of Ibn Mas`ûd (may Allâh be pleased with him), 'The Jamâ`ah is whatever agrees with the truth, even if you are alone.'"
[Usûl Da`wah As-Salafiyyah]