Battle of Yarmuk
During the Khilafat of Hazrat Umar (ra), when the actual battle began in Syria, Hazrat Saeed (ra) bin Zaid was appointed under Hazrat Abu Ubaidah(ra) as the general of some infantrymen. He displayed extraordinary bravery and determination during the siege of Damascus and in the decisive battle of Yarmuk. During battle, Harat Saeed (ra) bin Zaid was appointed as the governor of Damascus. However, he wrote to Hazrat Abu Ubaidah (ra) stating, “I cannot allow for you to participate in the Jihad whilst I be left deprived of it. Therefore, as soon as the letter is received, you should appoint someone else to this post so that I can join you as soon as possible.” Thus, with little choice, Hazrat Abu Ubaidah (ra) sent Yazid bin Abi Sufyan and Hazrat Saeed (ra) bin Zaid then returned to the battle once more.
(Roshan Sitarey az Ghulam Bari Saif, Vol. 2, p. 164) (Siyar as-Sahabah, Vol. 2, p. 138, Saeed bin Zaid, Darul Ishaat)