بُلُوغُ الْمَرَامِ
Bulugh al-Maram 263
The Book of Prayer
وَعَنْهُ قَالَ : قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ لَا تَقُومُ اَلسَّاعَةُ حَتَّى يَتَبَاهَى اَلنَّاسُ فِي اَلْمَسَاجِدِ } أَخْرَجَهُ اَلْخَمْسَةُ إِلَّا اَلتِّرْمِذِيُّ , وَصَحَّحَهُ اِبْنُ خُزَيْمَة َ [1]
Narrated [Anas (RA)]: Allah's Messenger (ﷺ) said: "The House (Judgement Day) will not come until people boast (to each other) with (the construction and decoration of) mosques. [Reported by al-Khamsah except at-Tirmidhi, and Ibn Khuzaimah graded it Sahih (authentic)].
Sunnah.com reference: Book 2, Hadith 135