I came to the Messenger of Allah ﷺ with a group from Mazina, and we pledged allegiance to him. The buttons of his shirt were undone. I gave him my pledge, then I put my hand into the opening of his shirt and touched the Seal of Prophethood.Urwa said, "I never saw Muawiya nor his son except with their shirt buttons undone, whether in winter or summer. They never fastened their buttons at all."
أتيت رسول الله ﷺ في رهط من مزينة، فبايعناه، وإن قميصه لمطلق الأزرار، قال: فبايعته ثم أدخلت يدي في جيب قميصه، فمسست الخاتم. قال عروة: فما رأيت معاوية ولا ابنه قط إلا مطلقي أزرارهما في شتاء ولا حر، ولا يزرران أزرارهما أبدا.
Reported by Abu Dawud (4082), Ibn Majah (3578), Tirmidhi in Shamail (57), Ahmad (15581), and Ibn Hibban (5452), all of them via Zuhayr, who said, Urwa bin Abdullah bin Qushayr Abu Mahal Jufi narrated to us, Muawiya bin Qurra narrated to us, from his father (Qurra bin Iyas), who said, then he related it. Its chain of transmission is sahih.