Hadith.2294 - The Messenger of Allah (swt) (peace and blessings be upon him and his family) entered the state of Ihram wearing two garments made of cotton.
Man Lā Yaḥḍuruh al-Faqīh #1026"The two garments in which the Messenger of Allah (swt) (peace be upon him and his family) entered Ihram were Yemeni cloths, one 'Abriyy and...
Al-Kāfi #1205“The Messenger of Allah (sw) assumed the state of Ihram in two pieces of cotton fabric.”