Sahih Muslim, Chapter: Faith (Kitab Al Iman)

that he went to Ubada b. Samit when he was about to die. I burst into tears. Upon this he said to me: Allow me some time (so that I may talk with you). Why do you weep? By Allah, if I am asked to bear witness, I would certainly testify for you (that you are a believer). Should I be asked to intercede, I would certainly intercede for you, and if I have the power, I would certainly do good to you, and then observed: By Allah, never did I hear anything from the Messenger of Allah (may peace be upon him) which could have been a source of benefit to you and then not conveyed it to you except this single hadith. That I intend to narrate to you today, since I am going to breathe my last. I heard the Messenger of Allah (may peace be upon him) say: He who testifies that there is no god but Allah and that Muhammad is the messenger of Allah, Allah would prohibit the fire of Hell for him.