An Arabi came to the Messenger of Allah ﷺ and asked, "Messenger of Allah, what is Islam?"He replied, "Five prayers in a day and a night."The man asked, "Am I obliged to perform any others?"He answered, "No."Then he asked him about fasting, and he said, "Fasting the month of Ramadan."The man asked, "Am I obliged to fast any other?"He answered, "No."Then he mentioned zakat, and the man asked, "Am I obliged to give any other?"He answered, "No."The man said, "By Allah, I will not add anything to these nor leave anything out."The Messenger of Allah ﷺ said, "He has succeeded if he is truthful."
حدثنا عبد الرحمن بن مهدي حدثنا مالك عن عمه عن أبيه أنه سمع
جاء أعرابي إلى رسول الله ﷺ فقال يا رسول الله ما الإسلام قال خمس صلوات في يوم وليلة قال هل علي غيرهن قال لا وسأله عن الصوم فقال صيام رمضان قال هل علي غيره قال لا قال وذكر الزكاة قال هل علي غيرها قال لا قال والله لا أزيد عليهن ولا أنقص منهن فقال رسول الله ﷺ قد أفلح إن صدق
Its isnad is sahih. Malik's paternal uncle is Abu Suhayl bin Malik bin Abu Amir al-Asbahi, and Abu Suhayl's given name was Nafi. He was trustworthy, and Quranic recitation was learned from him in Madinah. His father, Malik bin Abu Amir al-Asbahi, was a trustworthy successor, and there is no doubt that he heard from Umar, Uthman, Talha, and others.The hadith is found in Muwatta 1:188-189. It was also narrated by Bukhari, Muslim, Abu Dawud, and Nasai.