Persian forces. After the victory of Daumatul Jandal, Khalid returned to the Iraq front in September 633 C.E. By this time, the Persians had raised more forces and they were once again on the war path. One force of the Persians commanded by Ruzbeh was quartered at Huseid, northeast of 'Ein-at-Tarur. Another Persian force under Zarmahr was cantoned at Khanafis northwest of Huseid.

Plan of the campaign of Khalid. Khalid had his headquarters at 'Ein-at-Tarur. From there he sent one column under Qa'qa' to Huseid, and another column under Abu Leila to Khanafis. The instructions of Khalid were that the operations at Huseid and Khanafis should take place simultaneously.

The battle of Huseid. Qa'qa' reached Huseid before Abu Leila could reach Khanafis, and thus the original plan of simultaneous action could not be followed. The battle at Huseid began with a personal duel between Qa'qa' and Ruzbeh. In the duel, Ruzbeh was overpowered and killed. Then Zarmahr, the Commander of the forces at Khanafis, who was also at Huseid, stepped to give the challenge. Qa'qa' accepted the challenge and in the duel that followed, Zarmahr was also killed. Thereafter the Muslims charged. After some resistance, the Persians lost nerve, and withdrew from the battlefield leaving a large number of the dead at the site of the battle.

Confrontation at Khanafis. The survivors of the Persian army from Huseid fled to Khanafis. When the Persian garrison at Khanafis came to know of the Persian defeat at Huseid and of the death of their own Commander Zarmahr, they felt that any stand at Khanafis against the superior Muslim forces would be futile. Mabhuzab the new Commander considered discretion to be the better part of valor. He abandoned Khanafis and with his forces moved to Muzayyah further north where more forces were available and defenses were stronger. When the Muslim forces under Abu Leila arrived at Khanafis, they found that there were no Persian forces to meet them. The Muslims accordingly occupied Khanafis without firing any shot. Khalid, however, was not happy with the operations for the entire Persian garrison at Khanafis had escaped slaughter at the hands of the Muslims.

March to Muzayyah. When Khalid came to know that the Persian garrison from Khanafis had escaped to Muzayyah, he directed that the Persians should be pursued to Muzayyah. Three Muslim columns started separately for Muzayyah from 'Ein-at-Tamr, Huseid and Khanafis. They had to follow different routes, but they were required to reach a point close to Muzayyah at the same time.

The battle of Muzayyah. The movements of the Muslim forces were carried out according to plan, and the three corps mustered at the appointed place according to schedule. In the Persian camp there was a large concentration of the Persian forces and the Christian Arab auxiliaries at Muzayyah. Muzayyah was at considerable distance from Huseid and Khanafis, and the Persians were under the impression that the Muslim forces would take considerable time to reach Muzayyah.