Sayyiduna al-Sa'ib bin Yazid (may Allah be pleased with him) said that on the day of the battle of Uhud the Messenger of Allah (peace and blessings be upon him) was wearing two coats of mail when he (peace and blessings be upon him) appeared.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 17933