Musnad Abu Ya'la al-Mawsili 1:49

Abu Bakr ibn Abi Shaybah narrated to us, Muhammad ibn Umar al-Aslami narrated to us, al-Dahhak ibn Uthman narrated to us, from Habib, the freed slave of Urwah, who said: I heard Asma bint Abi Bakr say: I saw my father praying in a single garment. I said, "O my father, you pray in a single garment while your clothes are laid out?" He said, "O my daughter, indeed the last prayer that the Messenger of Allah (may Allah bless him and grant him peace) prayed behind me was in a single garment."