Musannaf Ibn Abi Shayba 3:1646

Al-Thaqafi narrated to us, from Ayyub, from Anas ibn Sirin, from Anas ibn Malik, from Umm Sulaym, that the Prophet (peace and blessings of Allah be upon him) used to pray in her house upon the *khumra* (a small prayer mat made of palm leaves).