"while we were with the Messenger of Allah, sitting in the Masjid, a man entered on a camel. He made it kneel in the Masjid, then he hobbled it. Then he said; 'Which of you is Muhammad?' He was reclining among them, and we said to him: 'This white man who is reclining.' The man said to him: 'O son of 'Abdul-Muttalib.' The Messenger of Allah said to him: 'I have answered you.' The man said: 'O Muhammad, I am going to ask you questions and I will be harsh in asking.' He said; 'Ask whatever you like.' The man said; 'I adjure you by your Lord, and the Lord of those who came begfore you, has Allah sent you to all the people?' The messenger of Allah said: 'by Allah, yes,' He said: 'Iadjure you by Allah, has Allah commanded you to fast this month each year?' The Messenger of Allah said: 'I adjure you by Allah, has Allah commanded you to take this charity from our rich and divide it among our poor?' The Messenger of Allah said: 'By Allah, Yes.' The ma said; 'I believe in that which you have brought, and I am the envoy of my people who are coming after me. I am Dimam bin Thalabah, the brother of Banu sad bin Bakr."' (Sahih) 'Ubaidullah bin 'Umar contradicted him.