Sa'id bin al-Harith narrates: We came as a group to Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both). He was praying wrapped in a single garment while his upper sheet was lying close by him; had he wanted to take it, he could have reached it. When he finished the prayer with the salam, we asked him about his praying in a single garment, and he said: I do this so that fools like you see me and spread from Jabir a concession that the Messenger of Allah (peace and blessings be upon him) granted him. I was with the Messenger of Allah (peace and blessings be upon him) on one of his journeys, and one night I came to him (peace and blessings be upon him) for some personal matter of mine. I saw the Messenger of Allah (peace and blessings be upon him) praying, and I was wearing only a single garment, so I wrapped that garment around myself and stood beside him. When he (peace and blessings be upon him) finished the prayer with the salam, he said: "O Jabir! What brings you at night?" So I told him my need. The Messenger of Allah (peace and blessings be upon him) said: "O Jabir! What is this wrapping that I saw?" I said: "O Messenger of Allah! It was one garment, and a tight one too." He (peace and blessings be upon him) said: "When you pray with only one garment on you, if it is ample, wrap it around yourself, and if it is tight, tie it on as a waist-wrapper."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3288