Jami` at-Tirmidhi 319
جامع الترمذي#319Da'ifوَقَدْ رُوِيَ عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ قَالَ " مَنْ بَنَى لِلَّهِ مَسْجِدًا صَغِيرًا كَانَ أَوْ كَبِيرًا بَنَى اللَّهُ لَهُ بَيْتًا فِي الْجَنَّةِ " . حَدَّثَنَا بِذَلِكَ قُتَيْبَةُ حَدَّثَنَا نُوحُ بْنُ قَيْسٍ عَنْ عَبْدِ الرَّحْمَنِ مَوْلَى قَيْسٍ عَنْ زِيَادٍ النُّمَيْرِيِّ عَنْ أَنَسٍ عَنِ النَّبِيِّ صلى الله عليه وسلم بِهَذَا .
It has been related that :the Prophet said: "Whoever builds a Masjid for (the sake of) Allah, be it small or large, then Allah will build a house for him in Paradise
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirDaif
Al-AlbaniDaif
Zubair Ali ZaiDaif
In-book reference: 2:171