The Prophet ﷺ wore two coats of mail, one over the other, on the day of Uhud.
أن النبي ﷺ ظاهر بين درعين يوم أحد.
Ahmad (15722), Shafii in al-Umm (4/252), and Saeed bin Mansur (2858) all narrated it from Sufyan bin Uyayna, from Yazid bin Khusayfa, from Saaib bin Yazid, who related it.Tirmidhi narrated it in Shamail (104) from Ahmad bin Abu Umar Adani, Nasai in al-Kubra (8529) from Abdullah bin Muhammad Daif (who is trustworthy, and Daif is his nickname), Ibn Majah (2806) from Hisham bin Ammar, Abu Shaykh in Akhlaq an-Nabi ﷺ (414) through the route of Ali bin Madini, and Ibn Jarud (1060) through the route of Abdullah bin Hashim, all five of them from Ibn Uyayna, from him.The narrations of Saeed bin Mansur, Ahmad, Abdullah bin Hashim, and Hisham bin Ammar contain the qualifying phrase "from Saaib, if Allah wills."Abu Dawud (2590) narrated it from Musaddad, who said, "Sufyan related to us," saying, "I think I heard Yazid bin Khusayfa relate from Saaib bin Yazid, from a man he named, that the Messenger of Allah ﷺ performed the fast of zihar," and he related the hadith.Ahmad said, "He (meaning Ibn Uyayna) related it to us another time, without including that qualifying phrase in it."There is disagreement over this narration as transmitted from Ibn Uyayna. Some of his companions narrated it from him, from Yazid bin Khusayfa, from Saaib, from a man he named, while others narrated it from him, from Yazid bin Khusayfa, from Saaib, from a man, from Talha bin Ubaydullah.Abu Yaala (660) narrated it from Suwayd bin Saeed, who said, "Sufyan bin Uyayna related to us, from Yazid bin Khusayfa, from Saaib bin Yazid, from a man from Banu Tamim called Muaz," and he related something similar.The sahih version is what Ibn Uyayna narrated from Yazid bin Khusayfa, from Saaib bin Yazid, stated with certainty, and this is what Daraqutni favored in al-Ilal (4/218). Its chain of transmission is sahih, and Busiri also graded it sahih in Zawaid Ibn Majah.