Sahih Al Bukhari Hadith Number 1891

Narrated Talha bin ‘Ubaidullah: A bedouin with unkempt hair came to Allah’s Messenger (peace be upon him) and said, “O Allah’s Messenger (peace be upon him)! Inform me what Allah has made compulsory for me as regards the prayers.” He replied: “You have to offer perfectly the five compulsory prayers in a day and night (24 hours), unless you want to pray Nawafil.” The bedouin further asked, “Inform me what Allah has made compulsory for me as regards fasting.” He replied, “You have to fast during the whole month of Ramadan, unless you want to fast more as Nawafil.” The bedouin further asked, “Tell me how much Zakat Allah has enjoined on me.” Thus, Allah’s Messenger (peace be upon him) informed him about all the rules (i.e. fundamentals) of Islam. The bedouin then said, “By Him Who has honored you, I will neither perform any Nawafil nor will I decrease what Allah has enjoined on me. Allah’s Messenger (peace be upon him) said, “If he is saying the truth, he will succeed (or he will be granted Paradise).