The Messenger of Allah ﷺ said, "The Hour will not come until people compete with one another in showing off through their mosques."
حدثنا عفان حدثنا حماد بن سلمة حدثنا أيوب عن أبي قلابة
قال رسول الله ﷺ لا تقوم الساعة حتى يتباهى الناس في المساجد
Its isnad is sahih, and it is found in the Sahihs. The hadith has already appeared at 12476.