Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bukhari:4561ʿAmr b. Khālid > Zuhayr > Abū Isḥāq > al-Barāʾ b. ʿĀzib

The Prophet ﷺ appointed ʿAbdullah 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."  

البخاري:٤٥٦١حَدَّثَنَا عَمْرُو بْنُ خَالِدٍ حَدَّثَنَا زُهَيْرٌ حَدَّثَنَا أَبُو إِسْحَاقَ قَالَ سَمِعْتُ الْبَرَاءَ بْنَ عَازِبٍ ؓ قَالَ

جَعَلَ النَّبِيُّ ﷺ عَلَى الرَّجَّالَةِ يَوْمَ أُحُدٍ عَبْدَ اللَّهِ بْنَ جُبَيْرٍ وَأَقْبَلُوا مُنْهَزِمِينَ فَذَاكَ إِذْ يَدْعُوهُمُ الرَّسُولُ فِي أُخْرَاهُمْ وَلَمْ يَبْقَ مَعَ النَّبِيِّ ﷺ غَيْرُ اثْنَىْ عَشَرَ رَجُلاً  


See similar narrations below:

Collected by Bukhārī
bukhari:4067ʿAmr b. Khālid > Zuhayr > Abū Isḥāq > al-Barāʾ b. ʿĀzib

The Prophet ﷺ appointed ʿAbdullah 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)  

البخاري:٤٠٦٧حَدَّثَنِي عَمْرُو بْنُ خَالِدٍ حَدَّثَنَا زُهَيْرٌ حَدَّثَنَا أَبُو إِسْحَاقَ قَالَ سَمِعْتُ الْبَرَاءَ بْنَ عَازِبٍ ؓ قَالَ

جَعَلَ النَّبِيُّ ﷺ عَلَى الرَّجَّالَةِ يَوْمَ أُحُدٍ عَبْدَ اللَّهِ بْنَ جُبَيْرٍ وَأَقْبَلُوا مُنْهَزِمِينَ فَذَاكَ إِذْ يَدْعُوهُمُ الرَّسُولُ فِي أُخْرَاهُمْ