reengaged until after Abu Bakr's ascension to the caliphate, at which point he chose to reaffirm Usama's command, which ultimately led to its success. Death of Muhammad There are a number of traditions regarding Muhammad's final days which have been used to reinforce the idea of the great friendship and trust which is said to have existed between him and Abu Bakr. In one such episode, as Muhammad was nearing death, he found himself unable to lead prayers as he usually would. He instructed Abu Bakr to take his place, ignoring concerns from Aisha that her father was too emotionally delicate for the role. Abu Bakr subsequently took up the position, and when Muhammad entered the prayer hall one morning during Fajr prayers, Abu Bakr attempted to step back to let him to take up his normal place and lead. Muhammad, however, allowed him to continue. In a related incident, around this time, Muhammad ascended the pulpit and addressed the congregation, saying, "God has given his servant the choice between this world and that which is with God and he has chosen the latter." Abu Bakr, understanding this to mean that Muhammad did not have long to live, responded "Nay, we and our children will be your ransom." Muhammad consoled his friend and ordered that all the doors leading to the mosque be closed aside from that which led from Abu Bakr's house, "for I know no one who is a better friend to me than he." Upon Muhammad's death, the Muslim community was unprepared for the loss of its leader and many experienced a profound shock. Umar was particularly affected, instead declaring that Muhammad had gone to consult with God and would soon return, threatening anyone who would say that Muhammad was dead. Abu Bakr, having returned to Medina, calmed Umar by showing him Muhammad's body, convincing him of his death. He then addressed those who had gathered at the mosque, saying, "If anyone worships Muhammad, Muhammad is dead. If anyone worships God, God is alive, immortal", thus putting an end to any idolising impulse in the population. He then concluded with verses from the Quran: "(O Muhammad) Verily you will die, and they also will die." (), "Muhammad is no more than an Apostle; and indeed many Apostles have passed away, before him, If he dies Or is killed, will you then Turn back on your heels? And