Musnad Abu Ya'la al-Mawsili 155:49

Narrated to us Mansur, narrated to us Abu Uways, from al-Zuhri, from Sa’id ibn al-Musayyib: That a man would come to Abu Hurayrah asking him for a legal opinion regarding praying in a single garment. He would say, "Do you recognize Abu Hurayrah?" The man would say, "It is you." He would then say, "I pray in a single garment, while my garment is placed upon the peg."