📅 630 CE | 9 AH
The following year after the conquest of Makkah growing rumours began to spread in Madinah that Heraclius had advanced a year’s salary to his army in view of a lengthy campaign against Madinah. However, the Prophet was also expecting his armies to open up Syria to Islam and so he too set about mustering by far the largest and best equipped army which he had led.
This time there was no attempt at secrecy with Muhammad ordering even the Makkans and the allied tribes to send at once to Madinah all their available armed and mounted men for the Syrian campaign.
The army arrived at al Hijr where the rock-hewn remains of Thamud stood, and the Prophet commanded the army to dismount for watering and a brief rest. Then, when the army reached the spring of Tabuk they encamped for twenty days. It was evident that the rumors of danger from the Byzantines had been unfounded; perhaps the news of the Muslim army’s approach had already reached the Byzantines who had withdrawn to the safety of their vicinity. The prophet chose not to pursue the Byzantines, but instead invited all of the tribes to join in allegiance to the Muslims.