حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ عَمِّهِ أَبِي سُهَيْلِ بْنِ مَالِكٍ، عَنْ أَبِيهِ، أَنَّهُ سَمِعَ طَلْحَةَ بْنَ عُبَيْدِ اللَّهِ، يَقُولُ جَاءَ رَجُلٌ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم مِنْ أَهْلِ نَجْدٍ ثَائِرُ الرَّأْسِ يُسْمَعُ دَوِيُّ صَوْتِهِ وَلاَ نَفْقَهُ مَا يَقُولُ حَتَّى دَنَا فَإِذَا هُوَ يَسْأَلُ عَنِ الإِسْلاَمِ فَقَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ خَمْسُ صَلَوَاتٍ فِي الْيَوْمِ وَاللَّيْلَةِ ‏"‏ ‏.‏ قَالَ هَلْ عَلَىَّ غَيْرُهُنَّ قَالَ ‏"‏ لاَ إِلاَّ أَنْ تَطَّوَّعَ ‏"‏ ‏.‏ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ وَصِيَامُ شَهْرِ رَمَضَانَ ‏"‏ ‏.‏ قَالَ هَلْ عَلَىَّ غَيْرُهُ قَالَ ‏"‏ لاَ إِلاَّ أَنْ تَطَّوَّعَ ‏"‏ ‏.‏ قَالَ وَذَكَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم الزَّكَاةَ ‏.‏ فَقَالَ هَلْ عَلَىَّ غَيْرُهَا قَالَ ‏"‏ لاَ إِلاَّ أَنْ تَطَّوَّعَ ‏"‏ ‏.‏ قَالَ فَأَدْبَرَ الرَّجُلُ وَهُوَ يَقُولُ وَاللَّهِ لاَ أَزِيدُ عَلَى هَذَا وَلاَ أَنْقُصُ مِنْهُ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ أَفْلَحَ الرَّجُلُ إِنْ صَدَقَ ‏"‏ ‏.‏

Yahya related to me from Malik from his paternal uncle Abu Suhaylibn Malik that his father heard Talha ibn Ubaydullah say, "Once one ofthe people of Najd came to the Messenger of Allah, may Allah bless himand grant him peace. He had dishevelled hair and although his voicecould be heard we could not make out what he was saying until he drewnearer and then we found he was asking about Islam. The Messenger ofAllah, may Allah bless him and grant him peace, said to him, 'Thereare five prayers during the day and the night.' He said, 'Do I have todo anything else besides that?' The Messenger of Allah, may Allahbless him and grant him peace, added, 'And fasting the month ofRamadan.' He said, 'Is there anything else I have to do?' He said,'No, except what you do of your own accord.' The Messenger of Allah,may Allah bless him and grant him peace, mentioned zakat. The mansaid, 'Is there anything else that I have to do?' He said, 'No, exceptwhat you do of your own accord.' He continued, "The man wentaway saying, 'By Allah, I won't do any more than this, nor will I doany less.' The Messenger of Allah, may Allah bless him and grant himpeace, said, 'That man will be successful, if he is telling thetruth.' Translation Not Available

Book Ref: Muwatta Imam Malik Book 9 Hadith 429
Web Ref:  Muwatta Imam Malik Book 9 Hadith 97