During one of the Ghazawat in which Messenger of Allah ﷺ was fighting, none remained with the Prophet ﷺ but Talha and Saʿd.  

لَمْ يَبْقَ مَعَ النَّبِيِّ ﷺ فِي بَعْضِ تِلْكَ الأَيَّامِ الَّتِي قَاتَلَ فِيهِنَّ رَسُولُ اللَّهِ ﷺ غَيْرُ طَلْحَةَ وَسَعْدٍ عَنْ حَدِيثِهِمَا  

The Prophet ﷺ said, "Who will bring me the information about the enemy on the day (of the battle) of Al-Ahzab (i.e. Clans)?" Az-Zubair said, "I will." The Prophet ﷺ said again, "Who will bring me the information about the enemy?" Az-Zubair said again, "I will." The Prophet ﷺ said, "Every prophet had a disciple and my disciple is Az-Zubair. "  

قَالَ النَّبِيُّ ﷺ مَنْ يَأْتِينِي بِخَبَرِ الْقَوْمِ يَوْمَ الأَحْزَابِ قَالَ الزُّبَيْرُ أَنَا ثُمَّ قَالَ مَنْ يَأْتِينِي بِخَبَرِ الْقَوْمِ قَالَ الزُّبَيْرُ أَنَا فَقَالَ النَّبِيُّ ﷺ إِنَّ لِكُلِّ نَبِيٍّ حَوَارِيًّا وَحَوَارِيَّ الزُّبَيْرُ  

During the battle of Al-Ahzab, I and ʿUmar bin Abi-Salama were kept behind with the women. Behold! I saw (my father) Az-Zubair riding his horse, going to and coming from Bani Quraiza twice or thrice. So when I came back I said, "O my father! I saw you going to and coming from Bani Quraiza?" He said, "Did you really see me, O my son?" I said, "Yes." He said, "Messenger of Allah ﷺ said, 'Who will go to Bani Quraiza and bring me their news?' So I went, and when I came back, Allah's Apostle mentioned for me both his parents saying, "Let my father and mother be sacrificed for you."'  

أَوَهَلْ رَأَيْتَنِي يَا بُنَىَّ قُلْتُ نَعَمْ قَالَ كَانَ رَسُولُ اللَّهِ ﷺ قَالَ مَنْ يَأْتِ بَنِي قُرَيْظَةَ فَيَأْتِينِي بِخَبَرِهِمْ فَانْطَلَقْتُ فَلَمَّا رَجَعْتُ جَمَعَ لِي رَسُولُ اللَّهِ ﷺ أَبَوَيْهِ فَقَالَ فِدَاكَ أَبِي وَأُمِّي