Battle of Yarmuk
Urwah relates from his father that during the Battle of Yarmuk, the companions of the Holy Prophet (sa) said to Hazrat Zubair (sa), “Will you not attack the enemy, so that we may also attack along with you.” Hazrat Zubair (ra) replied, “If I launch an attack against them, you will be left behind.” The companions replied that this would not be the case, and so, Hazrat Zubair (ra) attacked the enemy with such force that he penetrated right through the enemy lines. When he turned back and looked, he saw that there was no one else with him. When he tried to return, the enemy grabbed the reins of his horse and inflicted two wounds upon his shoulder on which there was already a large wound mark which he had sustained during the Battle of Badr.
Urwah further relates that as a child, he would place his fingers into his wound and play with it. He further states that during the Battle of Yarmuk, Abdullah bin Zubair (ra) was with Hazrat Zubair (ra) and he was only 10 years of age at the time. Hazrat Zubair (ra) seated him upon his horse and took him along with him and appointed someone to watch over him.
(Sahih al-Bukhari, Kitab-ul-Maghazi, Hadith no. 3975)