Musnad Ahmad 33:479

Yunus narrated to us, Abd al-Rahman—meaning Ibn al-Ghasil—narrated to us, Sharhabil Abu Sa’d narrated to me, that he entered upon Jabir ibn Abdullah while he was praying in a single garment, and his clothes were beside him. When he finished his prayer, I said: "May Allah forgive you, O Abu Abdullah! You pray in a single garment while these are your clothes beside you?" He said: "I intended that a fool like you might enter upon me and see me praying in a single garment. Did every companion of the Messenger of Allah (peace and blessings of Allah be upon him) have two garments?" He said: Then Jabir began to narrate to us, and he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "If the garment is ample, wrap it around your shoulders, then pray. And if it is too narrow for that, then tie it around your waist, then pray without folding it over."