Muhammad's wives
Muhammad was monogamous for 25 years. After his first wife Khadija bint Khuwaylid died, he proceeded to marry the wives listed below, and most of them were widows. Muhammad's life is traditionally delineated as two epochs: pre-hijra (emigration) in Mecca, a city in western Arabia, from the year 570 to 622, and post-hijra in Medina, from 622 until his death in 632. All but two of his marriages were contracted after the Hijra (migration to Medina). Of Muhammad's thirteen wives, at least two, Rayhana bint Zayd and Maria al-Qibtiyya, were referred to simply as concubines; however, there is debate among Muslims as to whether these two officially became his wives. Of his thirteen wives, only two bore him children, a fact which has been described as "curious" by Cornell University Professor of Near Eastern Studies David S. Powers.
Criticism of Muhammad
According to William Montgomery Watt, Zaynab herself was working for marriage with Muhammad and was not happy being married to Zayd. Watt also places doubt on the story outlined by Al-Waqidi and states that it should be taken with a "grain of salt." According to Watt, Zaynab was either thirty-five or thirty-eight years old at the time and that the story initially outlined by Al-Waqidi in which he detailed Muhammad's incident with Zaynab during the absence of Zayd may have been tampered with in the course of transmission. According to Mazheruddin Siddiqi, Zaynab as the cousin of Muhammad was seen by him many times before her marriage to Zayd. Siddiqi states: "He [Muhammad] had seen her many times before but he was never attracted to her physical beauty, else he would have married her, instead of insisting on her that she should marry Zaid."