It is narrated from Khalid bin Sameer that Abdullah bin Rabah (may Allah be pleased with him) came to us. I found him in such a state that people were gathered around him. He said that the horseman of the Messenger of Allah (peace and blessings be upon him), Abu Qatadah (may Allah be pleased with him), narrated to us that the Messenger of Allah (peace and blessings be upon him) sent the army of commanders and said: "Zaid bin Harithah (may Allah be pleased with him) will be your commander. If he is martyred, then after him, Ja'far (may Allah be pleased with him) will be the commander. If he too is martyred, then Abdullah bin Rawahah (may Allah be pleased with him) will be the commander." Upon hearing this, Ja'far (may Allah be pleased with him) jumped up and said, "O Prophet of Allah, may my father be sacrificed for you! I did not expect that you would appoint Zaid (may Allah be pleased with him) as commander over me." The Prophet (peace and blessings be upon him) said, "Set out, you do not know which matter is better." The army set out. They continued on their journey as long as Allah willed. Then the Messenger of Allah (peace and blessings be upon him) ascended the pulpit and ordered that the call for prayer be made. The Messenger of Allah (peace and blessings be upon him) said, "A news has spread. Shall I not inform you about the army engaged in battle?" They went and encountered the enemy, and Zaid (may Allah be pleased with him) was martyred. Pray for his forgiveness." So the people prayed for his forgiveness. After him, Ja'far bin Abi Talib (may Allah be pleased with him) took the flag. He attacked the enemy until he too was martyred. Bear witness to his martyrdom." The people also prayed for his forgiveness. Then Abdullah bin Rawahah (may Allah be pleased with him) took the flag. He too stood firm against the enemy until he was also honored with martyrdom. The Companions also prayed for his forgiveness. After them, Khalid bin Walid (may Allah be pleased with him) took the flag. He was not among the commanders appointed by the Messenger of Allah (peace and blessings be upon him). Due to the circumstances, he became the commander on his own. The Messenger of Allah (peace and blessings be upon him) raised his fingers and said: "O Allah! He is one of Your swords, so help him." Abdur Rahman, the narrator, said that due to the blessing of the Prophet's (peace and blessings be upon him) supplication, he was victorious. From that day, Khalid (may Allah be pleased with him) was called the Sword of Allah. Then the Noble Prophet (peace and blessings be upon him) said, "Set out and go help your brothers, and let none of you stay behind." The people set out, on foot and mounted, in the intense heat.