Which Companion participated in Uhud at the age of thirteen?

The Prophet, peace and blessings be upon him, used to review his army before battles and send back those who were unfit for combat, including those who had not reached fifteen years of age. However, in the Battle of Uhud, he permitted Rafi' ibn Khadij and Samura ibn Jundub to fight despite their young age. He permitted Rafi' due to his expertise in archery, and he permitted Samura because Samura could wrestle Rafi' down, after the Prophet, peace and blessings be upon him, ordered them to wrestle and Samura wrestled Rafi' down.