أَخْبَرَنَا مُحَمَّدُ بْنُ سَلَمَةَ قَالَ حَدَّثَنَا ابْنُ الْقَاسِمِ عَنْ مَالِكٍ قَالَ حَدَّثَنِي أَبُو سُهَيْلٍ عَنْ أَبِيهِ أَنَّهُ سَمِعَ طَلْحَةَ بْنَ عُبَيْدِ اللَّهِ يَقُولُ جَاءَ رَجُلٌ إِلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مِنْ أَهْلِ نَجْدٍ ثَائِرَ الرَّأْسِ يُسْمَعُ دَوِيُّ صَوْتِهِ وَلَا يُفْهَمُ مَا يَقُولُ حَتَّى دَنَا فَإِذَا هُوَ يَسْأَلُ عَنْ الْإِسْلَامِ قَالَ لَهُ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ خَمْسُ صَلَوَاتٍ فِي الْيَوْمِ وَاللَّيْلَةِ قَالَ هَلْ عَلَيَّ غَيْرُهُنَّ قَالَ لَا إِلَّا أَنْ تَطَوَّعَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَصِيَامُ شَهْرِ رَمَضَانَ قَالَ هَلْ عَلَيَّ غَيْرُهُ قَالَ لَا إِلَّا أَنْ تَطَوَّعَ وَذَكَرَ لَهُ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الزَّكَاةَ فَقَالَ هَلْ عَلَيَّ غَيْرُهَا قَالَ لَا إِلَّا أَنْ تَطَوَّعَ فَأَدْبَرَ الرَّجُلُ وَهُوَ يَقُولُ لَا أَزِيدُ عَلَى هَذَا وَلَا أَنْقُصُ مِنْهُ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَفْلَحَ إِنْ صَدَقَ

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 [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 [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 [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 [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 [SAW] said: 'He will succeed, if he is telling the truth.'" Translation Not Available

Book Ref: Sunan An Nisai Book 47 Hadith 5028
Web Ref:  Sunan An Nisai Vol 6 Book 47 Hadith 5031