Yahya related to me from Malik from his paternal uncle Abu Suhayl ibn Malik that his father heard Talha ibn Ubaydullah say, "Once one of the people of Najd came to the Messenger of Allah, may Allah bless him and grant him peace. He had dishevelled hair and although his voice could be heard we could not make out what he was saying until he drew nearer and then we found he was asking about Islam. The Messenger of Allah ﷺ said to him, 'There are five prayers during the day and the night.' He said, 'Do I have to do anything else besides that?' The Messenger of Allah ﷺ added, 'And fasting the month of Ramadan.' 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 ﷺ mentioned zakat. The man said, 'Is there anything else that I have to do?' He said, 'No, except what you do of your own accord.'
He continued, "The man went away saying, 'By Allah, I won't do any more than this, nor will I do any less.' The Messenger of Allah ﷺ said, 'That man will be successful, if he is telling the truth.'

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