The expedition to Tabuk was led by the Holy Prophet himself. In his absence from Madina, the Holy Prophet appointed Ali as the Governor of Madina. As such Ali did not participate in the expedition. The hypocrites spread the rumor that Ali had been left at Madina because he did not bare the courage to face the Byzantines. This cut Ali to the quick, and while the Muslim force was still at Jorf, a few miles from Madina, Ali visited the camp and apprised the Holy Prophet of what the hypocrites were saying. The Holy Prophet told Ali that he was to him what Prophet Haroon was to Prophet Musa. Just as Prophet Musa had appointed Haroon to look after his people during his absence, thus he had appointed Ali to look after Madina during his absence. The Holy Prophet pointed out that as the hypocrites were able to do any mischief, he had to appoint a member of his household to look after his household during his absence. Trouble could be expected from the tribes, and it was necessary that the administration of Madina was left in the hands of a person who could be a source of awe for the enemy. Fully satisfied Ali returned to Madina. He summoned Abdullah b Ubayy, and told him in plain words that if he or any of his followers tried to indulge in any mischief or spread any false rumor he would cut off their heads. That struck terror in the hearts of the hypocrites and they refrained from doing any mischief. Ali maintained law and order with a stern hand. He looked after the needs of the households of the Holy Prophet effectively.