Anas reported that his grandmother Mulaykah invited the Messenger of Allah ﷺ to a meal she had prepared. He ate some of it and then said, "Get up, and let me lead you in prayer."Anas said, I went to fetch a mat of ours that had turned black from long use and sprinkled it with water. The Messenger of Allah ﷺ stood upon it, and I lined up alongside the orphan boy behind him, with the elderly woman standing behind us. He led us in two units of prayer, then he ﷺ departed.
حدثنا القعنبي عن مالك عن إسحق بن عبد الله بن أبي طلحة
أن جدته مليكة دعت رسول الله ﷺ لطعام صنعته فأكل منه ثم قال قوموا فلأصلي لكم قال أنس فقمت إلى حصير لنا قد اسود من طول ما لبس فنضحته بماء فقام عليه رسول الله ﷺ وصففت أنا واليتيم وراءه والعجوز من ورائنا فصلى لنا ركعتين ثم انصرف ﷺ
Bukhari reported it in the Book of Prayer, Chapter on praying on a mat, hadith no. 380, and Muslim in the Book of Mosques, Chapter on the permissibility of congregational prayer in voluntary prayers, etc., hadith no. 658, from the hadith of Malik through this route, and it is found in Muwatta (Yahya): 153.