* Tahrir resounds with ‘Mursi, Mursi' chants * President-elect vows to fight for authority CAIRO — Muslim Brotherhood billed Friday as the “Day of transfer of power” and true to its message Egypt's President-elect Mohamed Mursi took the symbolic presidential oath in Tahrir Square standing before a crowd of thousands of supporters incessantly chanting “Mursi, Mursi.” The thousands who braved the searing heat all through the day waiting anxiously for the history to unfold in Egypt demanded the military's exit from political life. In his speech following the oath, Mursi said he would not allow for any presidential powers to be taken away. Mursi is expected to officially take the oath in front of the Supreme Constitutional Court Saturday. Some revolutionary youth and Brotherhood members called for him to be sworn in before a crowd in Tahrir, because they are the people responsible for his win. Mursi took the stage in Tahrir Square, closely surrounded by security guards dressed in suits and dark sunglasses. He chanted with the crowd at the beginning of his speech, “Free revolutionaries will continue the course.” “Commissioning me with the presidency is a great honor I'm proud of,” Mursi said. “I assure my greetings to all sectors I forgot to mention in my first speech.” “Revolution is led by its aims, and it will continue until it achieves all of its goals. You are the source of legitimacy and power, above all,” he continued. “There is no power above people power,” said Mursi. “Today you are the source of this power. You give this power to whoever you want and you withhold it from whoever you want.” His defiant speech was a clear challenge to the army, which also says it represents the will of the people. The 60-year-old US-trained engineer addressed himself to “the Muslims and Christians of Egypt” and promised them a “civil, nationalist, constitutional state”. Mursi also promised to work to free civilian detainees being tried by military courts and Omar Abdel Rahman, the spiritual leader of men convicted in the 1993 World Trade Center bombing. Abdel Rahman is a blind cleric jailed in the US for the plot to blow up New York City landmarks. Mursi also paid homage to Tahrir Square itself, and other squares from which he said “a new, free Egypt emerged.” He said that as president, he would remember that he is first responsible to the martyrs of the revolution, “whose blood watered the beautiful tree of liberty.” Mursi performed Friday prayers in Al-Azhar Mosque, where he was received by Al-Azhar Grand Sheikh Ahmed Al-Tayyeb, Grand Mufti Ali Gomaa, Endowments Minister Mohamed Abdel Fadil Al-Qawsi and a number of other Al-Azhar sheikhs. Worshippers chanted, “God is Great, God is Great” upon Mursi's arrival. Sheikh Mazhar Shahin, the imam of the Omar Makram Mosque in Tahrir Square, delivered a speech