"How often has a small force vanquished a large force by the permission of Allah? And Allah is with those who steadfastly persevere."
In the third week of July 634, the Muslim army marched from Busra; and the march of this army was an amazing sight-one that would earn the immediate disapproval of any regular, disciplined soldier. It had none of the appearance of a normal army. Its advance was more like the movement of a caravan than the march of a military force.
The soldiers of this army had no uniform of any kind, and there was no similarity in the dress that they wore. The men could wear anything they chose, including captured Persian and Roman robes. There were no badges of rank and no insignia to distinguish the commander from the commanded. In fact there were no officers so far as rank was concerned; officership was an appointment and not a rank. Any Muslim could join this army, and regardless of his tribal status would consider it an honour to serve in the ranks. The man fighting as a simple soldier one day could next day find himself appointed the commander of a regiment, or even a larger force. Officers were appointed to command for the battle or the campaign; and once the operation was concluded, they could well find themselves in the ranks again. The army was organised on the decimal system-a system started by the Holy Prophet at Madinah. 1 There were commanders of 10, 100 and 1,000 men, the latter corresponding to regiments. The grouping of regiments to form larger forces was flexible, varying with the situation.
Even in weapons and equipment there was no standard scale for this army. Men fought with whatever weapons they possessed, and had to find their own weapons either by purchase or by taking them from fallen foes. They could have any or all of the normally used weapons of the time-the lance, the javelin, the spear, the sword, the dagger and the bow. For armour they wore coats of mail and chain helmets. And these could be of any colour or design; in fact many of them had been taken from the Persians and the Romans. Most of the men mounted camels; those who possessed horses formed the cavalry.
One remarkable feature of the movement of this great army was that it was independent of lines of communication. Behind it stretched no line of supply, since it had no logistical base. Its food trotted along with the army; and if it ran out of meat, the men, women and children could live for weeks on a simple ration of dates and water. This army could not be cut off from its supplies, for it had no supply depots. It needed no roads for its movement, for it had no wagons and everything was carried on camels. Thus this army could go anywhere and traverse any terrain so long as there was a path over which men and animals could move. This ease of movement gave the Muslims a tremendous edge on the Romans in mobility and speed.
Although this army moved like a caravan and gave the impression of an undrilled horde, from the point of view of military security it was virtually invulnerable. The advance was led by a mobile advance guard consisting of a regiment or more. Then came the main body of the army, and this was followed by the women and children and the baggage loaded on camels. At the end of the column moved the rear guard. On long marches the horses were led; but if there was any danger of enemy interference on the march, the horses were mounted, and the cavalry thus formed would act either as the advance guard or the rear guard or move wide on a flank, depending on the direction from which the greatest danger threatened. In case of need, the entire army could vanish in an hour or so and be safe at a distance beyond terrain which no other large army could traverse. In this fashion the Muslims marched from Busra.
The route of the army has not been recorded; but it undoubtedly lay north of the Dead Sea, for the army arrived at Ajnadein before the corps of Amr bin Al Aas, who joined the army at Ajnadein. Had the army travelled south of the Dead Sea, Amr bin Al Aas, who was still at the Valley of Araba, would have been picked up en route. The army probably marched via Jarash and Jericho, then by-passed Jerusalem, which was strongly garrisoned by the Romans, and crossed the Judea Hills stretching south of Jerusalem. Beyond this range it descended into the plain of Ajnadein, arriving there on July 24. The following day Amr bin Al Aas, moving up from the Valley of Araba on the orders of Khalid, arrived at Ajnadein, and his joy knew no bounds. He had been in a state of anxiety for several weeks, expecting the Roman storm gathering at Ajnadein to break over his head any day.