أَخْبَرَنَا يَحْيَى بْنُ حَبِيبٍ، قَالَ حَدَّثَنَا حَمَّادٌ، عَنْ عَاصِمٍ، عَنْ أَبِي صَالِحٍ، عَنْ أُمِّ حَبِيبَةَ، قَالَتْ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ صَلَّى فِي يَوْمٍ ثِنْتَىْ عَشْرَةَ رَكْعَةً سِوَى الْفَرِيضَةِ بَنَى اللَّهُ لَهُ أَوْ بُنِيَ لَهُ بَيْتٌ فِي الْجَنَّةِ " .
It was narrated that Umm Habibah said: "The Messenger of Allah (PBUH) said: 'Whoever prays twelve rak'ahs in a day apart from the obligatory prayers, Allah (SWT) will build for him, or there will be built for him, a house in Paradise.'" Translation Not Available
Book Ref: Sunan An Nisai Book 20 Hadith 1808
Web Ref: Sunan An Nisai Vol 2 Book 20 Hadith 1809