What one may pray on and in

It is narrated from Shurayh (may Allah have mercy on him) that he asked the Mother of the Believers, Sayyidah Aishah (may Allah be pleased with her): "Did the Messenger of Allah (peace and blessings be upon him) perform prayer on a mat (hasir)? For I have read this saying of Allah in the Book of Allah, the Mighty and Majestic: 'And We have made Hell a prison (hasir) for the disbelievers' [Surah al-Isra': 8]." Sayyidah Aishah (may Allah be pleased with her) said: "No, he (peace and blessings be upon him) did not pray on a mat."
Imam Abu Ya'la also transmitted this narration of Imam Abu Bakr bin Abi Shaybah with his chain.

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that he said: "I saw the Messenger of Allah (peace and blessings be upon him) prostrating on his garment."
Imam Abu Ya'la narrated it in his Musnad. It is weak because of the presence of Sallam bin Sulaym and Zayd al-Ammi in its chain.

It is narrated from Thabit bin Ubayd that he said: "I went to visit Sayyiduna Zayd bin Thabit (may Allah be pleased with him) and saw him praying on a mat, and then he prostrated (during the prayer) on that same mat."
The chain of this report is sahih (authentic), and Imam Musaddad narrated it. It establishes that praying on a mat and prostrating on it is permissible and was the practice of the Companions (may Allah be pleased with them).

It is narrated from Simak bin Harb (may Allah have mercy on him) that he said: "I saw Sayyiduna al-Nu'man bin Bashir (may Allah be pleased with them both) praying on a wooden plank."
Imam Ibn Abi Shaybah narrated this report in al-Musannaf. Its chain contains Muhammad bin Jabir al-Hanafi, who is a weak narrator; however, in the light of other sahih reports, performing prayer on pure things that grow from the earth, such as wood or a mat, is permissible in the Shari'ah.

It is narrated from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) that he said (concerning the special place built in the mosque for the rulers): "I do not like to pray in this closed-off room of theirs." The narrator states that by this he (may Allah be pleased with him) meant the "maqsurah" (that is, the part of the mosque that has been separated from the ordinary worshippers by a wall or a railing).
Imam Musaddad bin Musarhad narrated this report in his Musnad. Its chain mentions one of the children of Sayyiduna Umar (may Allah be pleased with him) who is unnamed (mubham); however, the meaning of the statement is clear and reliable.