The Prophet ﷺ prayed on a straw mat.
حدثنا نصر بن علي حدثنا عيسى بن يونس عن الأعمش عن أبي سفيان عن جابر
أن النبي ﷺ صلى على حصير
No references are available.
Muslim also narrated it, Chapter on the permissibility of congregational prayer in voluntary prayers, etc., hadith 661, from the narration of Isa bin Yunus, from him. Jabir is Ibn Abdullah Ansari .There are also narrations on this subject from Anas [Bukhari, hadith 380, and Muslim, hadith 658] and Mughira bin Shuba [Abu Dawud, hadith 659, and Ibn Khuzayma, hadith 1006].