Imam Bukhari narrates: Abul Walid narrated to us, he said: Shu'bah narrated to us, he said: Sulaiman Ash-Shaibani narrated to us, from Abdullah bin Shaddad, from Hazrat Maimunah (may Allah be pleased with her), she narrated that
the Prophet ﷺ used to pray upon a Khumrah (small prayer-mat).
Reference: Sahih Al Bukhari 381