Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: Banu Sa'd bin Bakr sent Sayyiduna Dimam bin Tha'labah to the Messenger of Allah (peace and blessings be upon him). He came to him (peace and blessings be upon him), made his camel kneel at the door of the mosque, then tied it, then entered the mosque while the Messenger of Allah (peace and blessings be upon him) was sitting in the mosque. Dimam was a man with coarse hair and two braids. He came and stopped before the Messenger of Allah (peace and blessings be upon him) and his (peace and blessings be upon him) Companions, and said: Which of you is (the son of) Banu Abd al-Muttalib? The Messenger of Allah (peace and blessings be upon him) said: "I am the son of Abd al-Muttalib." He said: Muhammad? He (peace and blessings be upon him) said: "Yes." He said: O son of Abd al-Muttalib, I am going to ask you, and I will be harsh in my questioning, so do not take it to heart. He (peace and blessings be upon him) said: "I do not take it to heart; ask whatever comes to your mind." He said: I ask you by Allah, your God and the God of those before you and of those who will come after you: Has Allah commanded you to command us to worship Allah, not associating anything with Him, and to abandon these rivals whom our forefathers used to worship besides Him? He (peace and blessings be upon him) said: "O Allah, yes." He said: Then I ask you by Allah, your God and the God of those before you and of those who will come after you: Has Allah commanded you to command us to offer these five prayers? He (peace and blessings be upon him) said: "O Allah, yes." Then he began to mention the obligations of Islam one by one: zakah, fasting, Hajj and the laws of Islam, adjuring him at each obligation just as he had adjured him before, until, when he had finished, he said: I bear witness that there is no true god except Allah, and I bear witness that Muhammad is the Messenger of Allah, and I will fulfil these obligations and avoid what you have forbidden me, neither adding to it nor reducing. Then he went back to his camel, and the Messenger of Allah (peace and blessings be upon him) said: "If the man with the two braids is truthful, he will enter Paradise."
Hadith Referenceالمعجم الكبير للطبراني / باب الضاد / 8118