One who builds a masjid, Allah will build a house for him in Jannah; ʿUthman's rebuilding of the masjid of the Prophet ﷺ
regarding the ˹unfavorable˺ opinion of people during his rebuilding of the masjid of the Messenger of Allah ﷺ, he said: You have said much ˹in negativity˺, while I have heard Messenger of Allah ﷺ say, "He who builds a masjid..." and Bukayr said I think he also said: "... seeking the pleasure of Allah, Allah will build for him similar to it in Jannah." And in the narration of Hārūn, "Allah will build a house for him in Jannah."
عِنْدَ قَوْلِ النَّاسِ فِيهِ حِينَ بَنَى مَسْجِدَ رَسُولِ اللَّهِ ﷺ إِنَّكُمْ قَدْ أَكْثَرْتُمْ وَإِنِّي سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ: «مَنْ بَنَى مَسْجِدًا۔۔۔» قَالَ بُكَيْرٌ حَسِبْتُ أَنَّهُ قَالَ «۔۔۔يَبْتَغِي بِهِ وَجْهَ اللَّهِ، بَنَى اللَّهُ لَهُ مِثْلَهُ فِي الْجَنَّةِ۔» وَفِي رِوَايَةِ هَارُونَ «بَنَى اللَّهُ لَهُ بَيْتًا فِي الْجَنَّةِ۔»