A week after Abu Ubaida had assumed command of the Muslim army, a Christian Arab came to inform the new Commander that a fair was being held at Abul Quds, which if raided would promise the prospect of a great booty for the Muslims. Abu Ubaida was attracted, and he asked for volunteers who would like to go to raid Abul Quds.

Abdullah a son of Jafar a cousin of the Holy Prophet of Islam offered to command the raid. The offer was accepted and Abdullah with a contingent of five hundred soldiers marched to Abul Quds. Abul Quds was at the eastern foothills of the Lebanon range, 40 miles from Damascus on the road to Baalbeck. The fair was guarded by a force of 5,000 Byzantine men. In a fit of vainglory, Abdullah ordered a charge on the Byzantines. After some heroic fighting the Muslims came to be surrounded by the Byzantine forces. A Muslim soldier escaped from the battle-field and brought news to Abu Ubaida that the entire contingent of the Muslims at Abul Quds was faced with the danger of annihilation, and that help should be rushed for their relief immediately.

Abu Ubaida felt much worried. Umar had instructed that the Muslims should not be sent for mere plunder, and here he had transgressed such instructions. He had taken over the command recently, and if the Muslim continguent at Abul Quds was not saved that would very much prejudice the Muslim interests in Syria. The only person who could help him in that crisis was Khalid, but he felt that it would be embarrassing to request Khalid to come to his relief so soon after his deposition. But Abu Ubaida had no option but to request Khalid. Hesitatingly Abu Ubaida approached Khalid and requested him to come to the rescue of the Muslims at that critical juncture. Khalid agreed to rush to the relief of the contingent at Abul Quds.

Khalid rushed to Abul Quds with his mobile guard. He broke through the ranks of the Byzantines and saved the trapped Muslims. Some bitter fighting followed in which Khalid received many wounds. He, however, stood firm and ultimately the Byzantine garrison fled the fleld. That enabled Khalid attack the stalls at the fair and amass considerable booty.

Khalid returned to Damascus along with the liberated Muslims and the booty from the fair. Abu Ubaida thanked Khalid profusely. That showed that in the mind of Khalid there was no bitterness about his deposition. Abu Ubaida reported the matter to Umar at Madina, and in the report he lavished most generous praise on Khalid. He wrote that but for Khalid the raid of Abul Quds would have ended in disaster for the Muslims. Umar merely noted the contents, and had no word of praise for Khalid. On the other hand, he reprimanded Abu Ubaida for having sent a raid party to Abul Quds contrary to his instructions. He observed in strong terms that such acts of foolhardiness should not be repeated.