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." (Using translation from Bukhārī 2847)
سَمِعْتُ جَابِرَ بْنَ عَبْدِ اللهِ يَقُولُ نَدَبَ رَسُولُ اللهِ ﷺ يَوْمَ الْخَنْدَقِ فَانْتُدِبَ الزُّبَيْرُ ثُمَّ نَدَبَهُمْ فَانْتُدِبَ الزُّبَيْرُ ثُمَّ نَدَبَهُمْ فَانْتُدِبَ الزُّبَيْرُ فَقَالَ «إِنَّ لِكُلِّ نَبِيٍّ حَوَارِيًّا وَحَوَارِيَّ الزُّبَيْرُ»