Muhammad said that only a man of his house could proclaim the revelation. Muhammad summoned Ali, and asked him to proclaim a portion of Surah Tawbah to the people on the day of sacrifice when they assembled at Mina. Ali went forth on Muhammad's slit-eared camel, and overtook Abu Bakr. When Ali joined the party, Abu Bakr wanted to know whether he had come to give orders or to convey them. Ali said that he had not come to replace Abu Bakr as Amir-ul-Hajj, and that his only mission was to convey a special message to the people on behalf of Muhammad. At Mecca, Abu Bakr presided at the Hajj ceremony, and Ali read the proclamation on behalf of Muhammad. The main points of the proclamation were: Henceforward the non-Muslims were not to be allowed to visit the Kaaba or perform the pilgrimage. No one should circumambulate the Kaaba naked. Polytheism was not to be tolerated. Where the Muslims had any agreement with the polytheists such agreements would be honoured for the stipulated periods. Where there were no agreements a grace period of four months was provided and thereafter no quarter was to be given to the polytheists. From the day this proclamation was made a new era dawned, and Islam alone was to be supreme in Arabia. Expedition of Abu Bakr As-Siddiq Abu Bakr led one military expedition, the Expedition of Abu Bakr As-Siddiq, which took place in Najd, in July 628 (third month 7AH in the Islamic calendar). Abu Bakr led a large company in Nejd on the order of Muhammad. Many were killed and taken prisoner. The Sunni Hadith collection Sunan Abu Dawud mentions the event. Expedition of Usama bin Zayd In 632, during the final weeks of his life, Muhammad ordered an expedition into Syria to avenge the defeat of the Muslims in the Battle of Mu'tah some years previously. Leading the campaign was Usama ibn Zayd, whose father, Muhammad's erstwhile adopted son Zayd ibn Harithah, had been killed in the earlier conflict. No more than twenty years old, inexperienced and untested, Usama's appointment was controversial, becoming especially problematic when veterans such as Abu Bakr, Abu Ubaidah ibn al-Jarrah and Sa'd ibn Abi Waqqas were placed under his command. Nevertheless, the expedition was dispatched, though soon after setting off, news was received of Muhammad's death, forcing the army to return to Medina. The campaign was not