that ʿUmar had dismissed Khālid only because of certain statements (1) that had reached him, because of what had happened in the affair of Mālik ibn Nuwayrah, and because of the measures Khālid habitually employed in warfare. Thus, when ʿUmar assumed the caliphate, the very first thing he did was to remove Khālid, declaring, “He shall never again hold any office for me.”
ʿUmar then wrote to Abū ʿUbaydah: “If Khālid denies having made those statements, he remains commander over what he was commanding; but if he does not deny them, he is dismissed. Remove the turban from his head and divide his property in half.”
When Abū ʿUbaydah conveyed this to Khālid, Khālid said, “Give me time to consult my sister.” He went to his sister Fāṭimah—who was married to al-Ḥārith ibn Hishām—and sought her counsel. She told him, “ʿUmar will never like you; he will dismiss you even if you repudiate your own words.” He replied, “By Allah, you have spoken the truth.” Abū ʿUbaydah then divided Khālid’s wealth with him, taking even one of his two sandals (2) and leaving him the other (3), while Khālid kept repeating, “I hear and obey the Commander of the Faithful.”
Al-Ṭabarī (4) relates—through Ṣāliḥ ibn Kaysān—that the first letter ʿUmar wrote to Abū ʿUbaydah, when he appointed him and removed Khālid, contained the following:
“I counsel you to fear Allah, Who alone endures while everything else perishes, He who guided us out of misguidance and brought us from darkness into light. I have appointed you over the troops of Khālid ibn al-Walīd; therefore discharge toward them the duty that is incumbent upon you. Do not hurl the Muslims into destruction in pursuit of booty, nor make them camp anywhere until you have reconnoitred it (5) for them and learned how it may be approached. Do not dispatch a detachment except with a sizeable body (6) of men. Beware—beware of casting the Muslims into ruin. Allah has tested me by means of you and tested you by means of me, so avert your gaze from this world and detach your heart from it; beware lest it destroy you (7) as it destroyed those before you, for you have seen their ends. Order them to march upon Damascus.”
This was after the news of the victory at Yarmūk reached him, the glad tidings were delivered, and the one-fifth share of the spoils was sent to him.
Ibn Isḥāq has mentioned that after Yarmūk the Companions fought at Ajnādayn, and then at Faḥl in the Jordan Valley near Bayṣān, at a place called al-Radgha (8), so named because of the abundance of mud they encountered there; they shut the enemy inside it, and the Companions surrounded the place.
He said that it was at that juncture that the command passed to Abū ʿUbaydah from ʿUmar and Khālid was relieved. Ibn Isḥāq’s statement that Abū ʿUbaydah received the command during the siege of Damascus is the most widely known account.