May Allah have mercy on Umar! The people did not heed his counsel, nor did they stop at painting mosques red and yellow. Rather, they went further and decorated them with designs like those embroidered on cloth. Kings and caliphs vied with one another in building and embellishing mosques until they produced astonishing marvels. These mosques remain standing to this day in Syria, Egypt, the lands of the Maghreb, Andalusia, and elsewhere. Even now, Muslims continue to vie with one another in decorating mosques.
There is no doubt that decorating mosques is a sign of luxury and extravagance. Mosques are truly maintained through acts of obedience and the remembrance of Allah within them. It is enough to provide people with shelter from the heat, cold, and rain.
A warning of ruin has been given when mosques are ornamented and copies of the Quran are adorned. Al-Hakīm al-Tirmidhī narrated that Abū al-Dardā’, may Allah be pleased with him, said: “When you ornament your mosques and adorn your copies of the Quran, ruin will be upon you.” (1)