From Sahih Bukhari (Hadith 4561):
Narrated Al-Bara bin Azib:The Prophet (ﷺ) appointed `Abdullah bin Jubair as the commander of the infantry during the battle of Uhud. They returned defeated, and that is what is meant by:-- "And the Apostle was calling them back in the rear. None remained with the Prophet (ﷺ) then, but twelve men
Reference: Bukhari 4561