Reasons behind his Marriages
after the death of his first wife, khadeejah, with whom allah is pleased, the prophet, may allah exalt his mention, married eleven women; all were divorcees, except for a'ishah, with whom allah is pleased. six of his wives were from the tribe of quraish, and five were from different arabian tribes, and one was from the coptic christians in
'if you own a coptic christian, treat them kindly for between us is a pledge and relationship.' (abdurrazaaq #19325)
the prophet, may allah exalt his mention, married these women for a number of reasons:
1. religious and legislative purpose: the prophet, may allah exalt his mention, married zainab b. jahsh, with whom allah is pleased. the arabs in the era of ignorance would prohibit a man from marrying the wife of his adopted son; they believed that the adopted son was like a man's actual son in all aspects. the prophet, may allah exalt his mention, married her, although she was the wife of his adopted son, zaid b. harithah, with whom allah is pleased. the messenger of allah, may allah exalt his mention, married her to abolish this belief. allah, the exalted, says:
(and when you said to him to whom allah had shown favor and to whom you had shown a favor: keep your wife to yourself and be careful of (your duty to) allah; and you concealed in your soul what allah would bring to light, and you feared men, and allah had a greater right that you should fear him. but when zaid had accomplished his want of her, we gave have her to you as a wife, so that there should be no difficulty for the believers in respect of the wives of their adopted sons, when they have accomplished their want of them; and allah’s command shall be fulfilled..) (33:37)
2. political reasons and for the sake of da'wah, and to invite people to islam, and to gain the favor of the arab tribes: the messenger of allah, may allah exalt his mention, married women from the largest and strongest arab tribes. the prophet, may allah exalt his mention, ordered his companions, with whom allah is pleased, to do this as well. the prophet, may allah exalt his mention, said to abdurrahmaan b. auf, with whom allah is pleased:
'if they obey you (i.e. accept islam) then marry the daughter of the head of the tribe.'
dr. cahan said: 'some of the aspects of his life may seem confusing to us due to present day mentality. the messenger is criticized due to his obsession of attaining worldly desires and his nine wives, whom he married after the death of his wife khadeejah, with whom allah is pleased. it has been confirmed that most of these marriages were for political reasons, which were aimed to gain loyalty of some nobles, and tribes.'
3. social reasons: the prophet, may allah exalt his mention, married some of his companions’ wives who had died, in jihad or while giving da'wah. he married them even though they were older than him, and he did so to honor them and their husbands.
veccia vaglieri in her book 'in defense of islam' said: 'throughout the years of his youth, muhammad, may allah exalt his mention, only married one woman, even though the sexuality of man is at its peak during this period. although he lived in the society he lived in, wherein plural marriage was considered the general rule, and divorce was very easy - he only married one woman, although she was older than him. he was a faithful husband to her for twenty-five years, and did not marry another woman, except after her death. he at that time was fifty years old. he married each of his wives thereafter for a social, or political purpose; such that he wanted to honor the pious women, or wanted the loyalty of certain tribes so that islam would spread amongst them. all the wives muhammad, may allah exalt his mention, married were not virgin, nor were they young or beautiful; except for a'ishah, with whom allah is pleased. so how can anyone claim that he was a lustful man? he was a man not a god. his wish to have a son may have also lead him to marry; for the children that he had from khadeejah all died. moreover, who undertook the financial responsibilities of his large family, without having large resources. he was just and fair towards them all and did not differentiate between them at all. he followed the practice of previous prophets such as musa, whom no one objected to their plural marriage. is the reason why people object to the plural marriage of muhammad, may allah exalt his mention, the fact that we know the minute details of his life, and know so little of the details of the lives of the prophets before him?
thomas carlyle said: 'mahomet himself, after all that can be said about him, was not a sensual man. we shall err widely if we consider this man as a common voluptuary, intent mainly on base enjoyments,--nay on enjoyments of any kind.'
 'heroes, hero-worship and the heroic in history'