Sunan Abu Dawud
2590
Sahih+2

Narrated As-Sa'ib ibn Yazid: As-Sa'ib reported on the authority of a man whom he named: The Messenger of Allah (ﷺ) put on two coats of mail during the battle of Uhud as a double protection. (The narrator is doubtful about the word zahara or labisa)

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid