Sahih Muslim Book - 6, Hadith - 1696

وَحَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ حَدَّثَنَا شُعْبَةُ عَنِ النُّعْمَانِ بْنِ سَالِمٍ عَنْ عَمْرِو بْنِ أَوْسٍ عَنْ عَنْبَسَةَ بْنِ أَبِى سُفْيَانَ عَنْ أُمِّ حَبِيبَةَ زَوْجِ النَّبِىِّ -صلى الله عليه وسلم- أَنَّهَا قَالَتْ سَمِعْتُ رَسُولَ اللَّهِ -صلى الله عليه وسلم- يَقُولُ « مَا مِنْ عَبْدٍ مُسْلِمٍ يُصَلِّى لِلَّهِ كُلَّ يَوْمٍ ثِنْتَىْ عَشْرَةَ رَكْعَةً تَطَوُّعًا غَيْرَ فَرِيضَةٍ إِلاَّ بَنَى اللَّهُ لَهُ بَيْتًا فِى الْجَنَّةِ أَوْ إِلاَّ بُنِىَ لَهُ بَيْتٌ فِى الْجَنَّةِ ». قَالَتْ أُمُّ حَبِيبَةَ فَمَا بَرِحْتُ أُصَلِّيهِنَّ بَعْدُ. وَقَالَ عَمْرٌو مَا بَرِحْتُ أُصَلِّيهِنَّ بَعْدُ. وَقَالَ النُّعْمَانُ مِثْلَ ذَلِكَ.

It was narrated from Umm Habibah, the wife of the Prophet (s.a.w), that she heard the Messenger of Allah (s.a.w) say: "There is no Muslim slave who prays twelve Rak'ah to Allah each day, voluntarily, apart from the obligatory prayers, but Allah will build for him a house in Paradise - or a house will be built for him in Paradise." Umm Habibah said: "I did not stop praying them after that." 'Amr said: "I did not stop praying them after that. And An-Nu'man said something similar."