Muwatta Malik Book 8, Hadith 33
Yahya related to me from Malik that he had heard that Jabir ibn
Abdullah used to pray in one garment.
Yahya related to me from Malik from Ibn Shihab that Said ibn al- Musayyab said that Abu Hurayra was asked, "May a man pray in one garment?" He said, "Yes." The man then said to him "Do you do that?" and he replied, "Yes, I pray in one garment while my clothes are on the clothes-rack."
Yahya related to me from Malik from Rabia ibn Abi Abd ar-Rahman that Muhammad ibn Amr ibn Hazm used to pray in a single long shirt.