Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that in the time of the Prophet (peace and blessings be upon him) the mosque was made of mud bricks, its roof of palm stalks and its pillars of palm trunks. Sayyiduna Abu Bakr (may Allah be pleased with him) added nothing to it, and Sayyiduna Umar (may Allah be pleased with him) enlarged it somewhat, but built it with palm trunks and stalks just the same. Then Sayyiduna Uthman (may Allah be pleased with him) changed it: he enlarged it greatly, built its walls and pillars of carved and engraved stone, and made its roof of teak wood.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4294