When the Prophet ﷺ called the people (Sadqa, a sub-narrator, said, 'Most likely that happened on the day of Al-Khandaq) Az-Zubair responded to the call (i.e. to act as a scout). The Prophet) called the people again and Az-Zubair responded to the call. The Prophet ﷺ then said, "Every prophet had a disciple and my disciple is Zubair bin Al-ʿAwwam."  

نَدَبَ النَّبِيُّ ﷺ النَّاسَ قَالَ صَدَقَةُ أَظُنُّهُ يَوْمَ الْخَنْدَقِ فَانْتَدَبَ الزُّبَيْرُ ثُمَّ نَدَبَ فَانْتَدَبَ الزُّبَيْرُ ثُمَّ نَدَبَ النَّاسَ فَانْتَدَبَ الزُّبَيْرُ فَقَالَ النَّبِيُّ ﷺ إِنَّ لِكُلِّ نَبِيٍّ حَوَارِيًّا وَإِنَّ حَوَارِيَّ الزُّبَيْرُ بْنُ الْعَوَّامِ