سنن النسائي

Abu Suhail narrated from his father,: That he heard Talhah bin 'Ubaidullah say: "A man from Najd with unkempt hair came to the Messenger of Allah (ﷺ) [SAW]; he was speaking loudly but his speech could not be understood until he came close. He was asking about Islam. The Messenger of Allah (ﷺ) [SAW] said: 'Five prayers every day and night.' He said: 'Do I have to do any more than that? He said: 'No, not unless you do it voluntarily.' The Messenger of Allah (ﷺ) [SAW] said: 'Fasting the month of Ramadan.' He said: 'Do I have to do any more than that?' He said: 'No, not unless you do it voluntarily.' Then the Messenger of Allah (ﷺ) [SAW] told him about Zakah. He said: 'Do I have to do any more than that?' He said: 'No, not unless you do it voluntarily.' The man left saying, 'I will not do any more than that or any less.' The Messenger of Allah (ﷺ) [SAW] said: 'He will succeed, if he is telling the truth.'"