The Messenger of Allah ﷺ used to pray on a small prayer mat and prostrate upon it.
إن رسول الله ﷺ كان يصلي على الخمرة، ويسجد عليها.
No references are available.
Tabarani reported it in Mujam al-Kabir (13415) and in Mujam al-Awsat, "Majma Bahrayn" (705), from Ahmad bin Shuayb Nasai, who said, Qutayba bin Saeed told us, Ataf bin Khalid told us, from Nafi, from Ibn Umar, and he mentioned it. Its isnad is hasan because of the discussion surrounding Ataf bin Khalid, except that his hadith is hasan, and it has been corroborated as will follow.Ibn Khuzayma (1013) and Bazzar in "Kashf Astar" (608) both reported it from Muhammad bin Mubarak Makhrami (thus in Ibn Khuzayma, while in Bazzar it is Muhammad bin Abdullah bin Mubarak Makhrami), who said, Mualla bin Mansur told us, Wahib told us, from Ayub, from Nafi, from Ibn Umar, who said, "The Messenger of Allah ﷺ used to pray on the khumrah, never leaving it aside whether traveling or at home." This is the wording of Ibn Khuzayma. The wording of Bazzar is, "He used to pray on the khumrah, I think he also said, and he would prostrate on it."Mualla bin Mansur is a subject of disagreement, except that his hadith is hasan. Muhammad bin Abdullah bin Mubarak is Qurashi Makhrami, with the letter kha and doubled ra, Abu Jafar Baghdadi Madaini, the hafiz, judge of Hulwan. Bukhari, Abu Dawud, and Nasai reported from him. He is trustworthy and a hafiz, who died in the year two hundred and sixty, or shortly before it, and he is among the men of Tahdhib. He is not the same as Muhammad bin Mubarak Makhrami Qurashi Suri, for that man died in the year 215 AH, while Ibn Khuzayma was born in the year 223 AH.Imam Ahmad also reported it (5660) from Abu Nadr, who said, Sharik told us, from Abu Ishaq, from Bahi, from Ibn Umar, and he mentioned it similarly. He also reported it (5733) from Ibrahim bin Abu Abbas, who said, Sharik told us the same, though Sharik was uncertain whether he raised it to the Prophet.All of these are daif, because Sharik bin Abdullah has poor memory. The hadith has, however, been established as sahih through a route other than his, as is supported by what Ibn Abu Shayba reported (1/399) as an action of Ibn Umar, that he used to pray on the khumrah, from Waki, who said, Sufyan told us, from Abdullah bin Dinar, from Ibn Umar. This does not contradict the version raised to the Prophet.