The Prophet (صلى الله عليه وسلم) said:
تركتُ فيكم أيُّها الناس، ما إنِ اعتصمتم به، فلن تضلُّوا أبدًا: كتاب الله، وسُنَّة نبيِّه
“I have left among you, O people, that which if you were to cling to it, you would never go astray, the Book of Allāh and the Sunnah of His Prophet.”
Reported by Al-Hākim in his Al-Mustadrak, Al-Marwazī in As-Sunnah, no. 68. Declared sahīh by Al-Albāni in Sahīh At-Targhīb, no. 40
Translation source: https://ikhlaas.org/