Abdullah bin Abbas reported,

The tribe of Banu Saad bin Bakr sent Dimam bin Thalaba as their delegate to the Messenger of Allah ﷺ. He arrived, made his camel kneel at the entrance of the mosque, tethered it, then entered. The Messenger of Allah ﷺ was sitting among his companions. Dimam was a sturdy, hairy man with two long braids. He approached and stood before the Messenger of Allah ﷺ in the company of his companions and asked, "Which of you is the son of Abdul Muttalib?"The Messenger of Allah ﷺ replied, "I am the son of Abdul Muttalib."Dimam asked, "Muhammad?"He said, "Yes."Dimam said, "Son of Abdul Muttalib, I am going to question you, and I will be harsh in my questioning, so do not hold it against me."He replied, "I will hold nothing against you. Ask whatever you wish."Dimam said, "I adjure you by Allah, your God, the God of those before you, and the God of those who will come after you. Did Allah truly send you to us as a messenger?"He answered, "By Allah, yes."Dimam said, "I adjure you by Allah, your God, the God of those before you, and the God of all that has been. Did Allah command you that we worship Him alone, associating nothing with Him, and that we cast off these rivals our forefathers used to worship alongside Him?"He answered, "By Allah, yes."Dimam said, "I adjure you by Allah, your God, and the God of those before you. Did Allah command you that we perform these five prayers?"He answered, "By Allah, yes."Then Dimam went on to ask about every obligation of Islam one by one, the zakat, the fast, the pilgrimage, and all the laws of Islam, adjuring him at each obligation just as he had at the one before, until he finished. Then he said, "I bear witness that there is no god but Allah, and I bear witness that Muhammad is the Messenger of Allah. I will fulfill these obligations and avoid what you have forbidden me, neither adding to them nor subtracting from them."Then he turned back toward his camel. As he departed, the Messenger of Allah ﷺ said, "If the man with the two braids is truthful, he will enter Paradise."Dimam went to his camel, untied its tether, and set out until he reached his people. They gathered around him, and the first words he spoke were, "How wretched are al-Lat and al-Uzza!"They said, "Stop, Dimam! Beware of leprosy, beware of elephantiasis, beware of madness!"He replied, "Woe to you! By Allah, those two neither harm nor benefit. Allah has sent a messenger and revealed to him a book by which He has rescued you from what you were in. I bear witness that there is no god but Allah alone, with no partner, and that Muhammad is His servant and messenger. I have come to you from him with what he commands you and what he forbids you."By Allah, by the end of that day, there was not a man or woman in his settlement who had not become a Muslim.Ibn Abbas said, "We never heard of any tribal delegate more excellent than Dimam bin Thalaba."

عن ابن عباس قال

بعث بنو سعد بن بكر ضمام بن ثعلبة وافدا إلى رسول الله ﷺ فقدم عليه وأناخ بعيره على باب المسجد ثم عقله، ثم دخل المسجد ورسول الله ﷺ جالس في أصحابه- وكان ضمام رجلا جلدا أشعر ذا غديرتين- فأقبل حتى وقف على رسول الله ﷺ في أصحابه، فقال: أيكم ابن عبد المطلب؟ فقال رسول الله ﷺ: أنا ابن عبد المطلب. فقال: محمد؟ قال: نعم. فقال: ابن عبد المطلب، إني سائلك ومغلظ في المسألة، فلا تجدن في نفسك. قال: لا أجد في نفسي فسل عما بدا لك. قال: أنشدك الله إلهك، والله من كان قبلك، والله من كان ذلك، والله من هو كائن بعدك. آلله أرسلك إلينا رسولا؟ فقال: اللهم نعم. قال: فأنشدك الله إلهك، والله من كان قبلك، والله من كان ذلك أن آمر أن نعبده وحده لا نشرك به شيئا، وأن نخلع هذه الأنداد التي كانت آباؤنا يعبدون معه؟ قال: اللهم نعم. قال: فأنشدك الله إلهك، والله من كان قبلك، آلله أمرك أن نصلي هذه الصلوات الخمس؟ قال: اللهم نعم. قال: ثم جعل يذكر فرائض الإسلام فريضة فريضة: الزكاة، والصيام، والحج، وشرائع الإسلام كلها، يناشده عند كل فريضة كما ناشده في التي قبلها، حتى إذا فرغ قال: فإني أشهد أن لا إله إلا الله، وأشهد أن محمدا رسول الله، وسأؤدي هذه الفرائض، وأجتنب ما نهيتني عنه، ثم لا أزيد ولا أنقص، قال: ثم انصرف راجعا إلى بعيره، فقال رسول الله ﷺ حين ولي: إن يصدق ذو العقيصتين يدخل الجنة. قال: فأتى إلى بعيره فأطلق عقاله، ثم خرج حتى قدم على قومه فاجتمعوا إليه فكان أول ما تكلم به أن قال: بئست اللات والعزي قالوا: مه يا ضمام، اتق البرص والجذام، اتق الجنون. قال: ويلكم إنهما والله لا يضران ولا ينفعان، إن الله عز وجل قد بعث رسولا، وأنزل عليه كتابا استنقذكم به مما كنتم فيه، وإني أشهد أن لا إله إلا الله وحده لا شريك له، وأن محمدا عبده ورسوله، وقد جئتكم من عنده بما أمركم به ونهاكم عنه. قال: فوالله ما أمسي من ذلك اليوم وفي حاضره رجل ولا امرأة إلا مسلما. قال: يقول ابن عباس: فما سمعنا بوافد قوم كان أفضل من ضمام بن ثعلبة.