The Messenger of Allah ﷺ said, "The Hour will not come until people compete with one another in showing off through their mosques."
حدثنا أبو سعيد حدثنا حماد بن سلمة عن أيوب عن أبي قلابة
قال رسول الله ﷺ لا تقوم الساعة حتى يتباهى الناس في المساجد
Its isnad is sahih. Ayub is Sakhtiyani, and Abu Qilaba is Abdullah bin Zayd Jarmi. The hadith has already appeared at 12320.