(3) باب فَضْلِ بِنَاءِ الْمَسَاجِدِ
Mahmud b. Labid reported that 'Uthman b. 'Affan decided to rebuild the mosque (of Allah's Apostle in Medina) but the people did not like this idea and they wished that it should be preserved in the same (old) form. Thereupon he (Hadrat 'Uthman) said:
I heard Allah's Messenger (ﷺ) as saying: He who builds a mosque for Allah, Allah would build for him (a house) in Paradise like it.
Reference: Sahih Muslim 533 d
In-book reference: Book 55, Hadith 54
USC-MSA web (English) reference(deprecated numbering scheme): Book 42, Hadith 7110