كتاب المغازى
64  
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Sahih al-Bukhari 4067

Narrated Al-Bara' bin `Azib:

The Prophet (ﷺ) appointed `Abdullah bin Jubair as the commander of the cavalry archers on the day of the battle of Uhud. Then they returned defeated, and that what is referred to by Allah's Statement:-- "And the Apostle (Muhammad) was in your rear calling you back." (3.153)

حَدَّثَنِي عَمْرُو بْنُ خَالِدٍ، حَدَّثَنَا زُهَيْرٌ، حَدَّثَنَا أَبُو إِسْحَاقَ، قَالَ سَمِعْتُ الْبَرَاءَ بْنَ عَازِبٍ ـ رضى الله عنهما ـ قَالَ جَعَلَ النَّبِيُّ صلى الله عليه وسلم عَلَى الرَّجَّالَةِ يَوْمَ أُحُدٍ عَبْدَ اللَّهِ بْنَ جُبَيْرٍ، وَأَقْبَلُوا مُنْهَزِمِينَ، فَذَاكَ إِذْ يَدْعُوهُمُ الرَّسُولُ فِي أُخْرَاهُمْ‏.‏
Reference : Sahih al-Bukhari 4067
In-book reference : Book 64, Hadith 112
USC-MSA web (English) reference : Vol. 5, Book 59, Hadith 396
  (deprecated numbering scheme)