Sahih al-Bukhari 1891

It is related from Talha ibn 'Ubaydullah that a bedouin with unkempt hair came to the Messenger of Allah, may Allah bless him and grant him peace, and said, "Messenger of Allah, tell me what Allah has made obligatory for me in respect of prayer." He said, "The five prayers unless you want to do some extra voluntary ones." He said, "Tell me what Allah has made obligatory for me in respect of fasting." He said, "The month of Ramadan unless you want to do something extra." He said, "Tell me what Allah has made obligatory for me in respect of zakat." Talha said, "The Messenger of Allah, may Allah bless him and grant him peace, informed him about the laws of Islam. He said, 'By the One who has honoured you, I will not do anything extra nor any less than what Prophet has made obligatory on me.' The Messenger of Allah, may Allah bless him and grant him peace, said, 'If he speaks the truth, he will have success - or he will enter the Garden if he speaks the truth.'"