The prophet’s command to stick to his sunnah as understood by the scholars

Irbadh ibn Sariyyah (RadhiAllahu Anhu) said,

“One day after prayer the Messenger of Allah, admonished us such that the eyes wept and hearts shuddered. A man said, “Indeed, this is a farewell speech, so what do you order us, O Messenger of Allah?” He said, “I enjoin you to fear Allah, and to listen and obey your leader even if he is a slave from Abyssinia; verily, whoever lives among you will see many differences; beware of newly invented matters, for indeed they are misguidance; so whoever sees that must uphold my tradition (sunnah) and the tradition of the upright successors who are guided; bite onto it with you molar teeth.”

(Sunan Abi Dawud, Kitab as-Sunnah (no.4607), Sunan Tirmidhi (5/44), Ibn Majah, al-Muqaddimah (no.42), Sunan Darimi (1/57), Imam Tirmidhi said, “This hadith is Hasan Sahih.”

Imam Ibn Rajab said in‘Jam’e al-Ulum al-Hikam’

“This hadith commands holding onto the Sunnah of the Messenger of Allah (SalAllahu Alayhi Wasallam) and the Rightly Guided Khulafa firmly during times of discord and differences. The Sunnah is a path that is tread upon and this compromises holding onto the Sunnah of the Messenger of Allah (SalAllahu Alayhi Wasallam) and the way of the companions with regards to beliefs, actions and statements and this is the complete Sunnah.”

(Jam’e al-Ulum al-Hikam (pg.230)