Ibn Umar (may Allah be pleased with him) says that a man stood up and called out to the Messenger of Allah (peace and blessings be upon him): Which clothes do you (peace and blessings be upon him) command us to wear when we are in ihram? He then mentioned the complete hadith.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9043