By 638 A.D., the whole of Syria was under the occupation of the Muslims. Heraclius the Byzantine emperor had left Syria and withdrawn his forces. His parting words were:
"Farewell Syria, never again will I come to this beautiful land. What a fine country I am leaving for the enemy."
Some of the Christian Arabs felt grieved at the discomfiture of the Christians at the hands of the Muslims. In a spirit of fanaticism they vowed vengeance against the Muslims. Having failed to defeat the Muslims on the battlefield they decided to resort to underhand means and murder some high ranking Muslims. A Ghassanid Arab Wasiq by name undertook to murder Umar the Caliph of Islam.
Wasiq waited on Heraclius at Constantinople, and volunteered to rid the Byzantine emperor of his enemies. The scheme appealed to Heraclius. He paid Wasiq a huge sum and promised to pay much more when he succeeded in his mission. Thus patronised, Wasiq decided to proceed to Madina.
Arab as he was, Wasiq found no difficulty in coming over to Madina in cognito. He posed himself as a Muslim coming from the interior of the desert to pay a visit to Madina. Wasiq carried a poisoned dagger carefully hidden in the folds of his cloak. Having reached Madina, he was on the look out for a suitable opportunity when he could come face to face with the Caliph of Islam, and kill him with his dagger in an unguarded moment.
He had thought that the ruler of the Muslim state would be surrounded by heavy body-guards at all times and it would be difficult to reach him. He was surprised to learn in Madina that there were no body-guards around the Caliph of Islam. Wasiq felt happy that unguarded as the Caliph was, he could easily get an opportunity to fulfil his mission.
Wasiq waited for a suitable opportunity. One day at noon Wasiq found Umar sleeping under a tree, all alone and without any guard. There was no body near at hand. Wasiq thought that this was a golden opportunity for him and he could despatch the Caliph of Islam without any difficulty.
Cautiously with measured steps and hushed breath Wasiq stepped upto Umar and took his sword. He was about to plunge his sword in the body of Umar when his eyes fell on the face of Umar. The sight of the unadorned majesty of the pious Caliph sent a shudder through the body of Wasiq, and the sword dropped from his trembling hands. With the noise of the dropping of the sword, Umar opened his eyes. He was quick to take hold of the fallen sword and then rising up faced his would be assassin.
Wasiq fell at the feet of the Caliph, implored his forgiveness and embraced Islam.