When Ubayd Allah and the Kufan vanguard arrived at al-Maskin, they found that Muawiyah had already arrived. Muawiyah sent an envoy to tell them that he had received letters from Hasan asking for an armistice and asked the Kufans not to attack until the negotiations were complete. Muawiyyah's claim was probably untrue, but he had good reason to think that he could make Hasan give in. The Kufans, however, insulted Muawiyah's envoy. Then, Muawiya sent the envoy to visit Ubayd Allah in private, and to swear to him that Hasan had requested a truce from Muawiyah, and offered Ubayd Allah 1,000,000 dirhams, half to be paid at once, the other half in Kufa, provided he switched sides. Ubayd Allah accepted and deserted at night to Muawiyah's camp. Muawiyah was extremely pleased and fulfilled his promise to him.