From Sahih Muslim (Hadith 7471):
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: Muslim 7471