Polygamous Marriage of Rasulullah (Sallallahu Alaihi Wasallam)

Allah Taãla has given certain priviledges only to Rasulullah (Sallallaahu Álayhi Wasallam) which are mentioned in Chapter 33 vs 50-51. Among other priviledges one was having more than four wives simultaneously.
Allah Taãla says, 'Oh Nabi (Sallallaahu Álayhi Wasallam) we have made permissible for you your wives.' (Ahzaab 33-50).
The polygamous marriages of Rasulullah (Sallallaahu Álayhi Wasallam) to more than four wives simultaneously should be viewed as obeying the order of Allah Taãla to do so. It was not merely a means of fulfilling his carnal desires as many people allege. The Arab environment was infested with many evils among which was adultery and fornication. Despite living in such an environment, he never indulged in this evil act. His modesty was so popular among his people that when the Prophet (Sallallaahu Álayhi Wasallam) claimed prophethood, his people made every effort to disgrace him by accusing him of being a poet, practising witchcraft, of being insane, etc. However, nobody ever accused him of any act of immodesty.
The Prophet (Sallallaahu Álayhi Wasallam) was very handsome and attractive. Many beautiful women from honourable families even proposed marriage to Rasulullah (Sallallaahu Álayhi Wasallam) but he declined. Instead, when he was only 25 years of age he married a widow who had children from her previous marriage. Considering the fact that he was the most handsome person that Allah Taãla has created, many women desired him in marriage. Had he followed his desires, there was no obstacle for him to do so. In his youth, he could have had many many beautiful women, but he married a widow 15 years his senior. He lived with her for 25 years and she bore all the children of Rasulullah (Sallallaahu Álayhi Wasallam) except one.
When Rasulullah (Sallallaahu Álayhi Wasallam) was 50 years of age, Hadhrat Khadija (Radhiallaahu Ánha) passed away. Those 25 years of Rasulullah (Sallallaahu Álayhi Wasallam)'s marriage was a monogamous one. The polygamous marriage was only after he attained the age of 50.

He married Hadhrat Sawdah and Áaisha (Radhiallaahu Ánhuma). Sawda (Radhiallaahu Ánha) lived with him immediately but Áaisha (Radhiallaahu Ánha) came to live with him in the year 2 AH. when he was approximately 54 years of age.

55 YEARS (3 AH.)
He married Hadhrath Hafsa (Radhiallaahu Ánha). After a few months, he married Hadhrat Zaynab bin Khuzaymah (Radhiallaahu Ánha) who lived with him for only 3 or 18 months (as recorded in different narrations) before she passed away.

56 YEARS (4 AH.)
He married Umme Salma (Radhiallaahu Ánha)

57 YEARS (5 AH.)
He married Zaynab (Radhiallaahu Ánha)

58 YEARS (6 AH)
He married Hadhrat Juwayriyah (Radhiallaahu Ánha)

59 YEARS (7 AH.)
First he married Umme Habibah then Safiyyah then Maymoonah (Radhiallaahu Ánhunna) in one year. From the above explanation, it is clear that Rasulullah (Sallallaahu Álayhi Wasallam)'s marriage was a monogamous one till he was 50 years. His polygamous marriages, mostly to widows were after the age of 50 with the command of Allah Taãla. Had Nabi (Sallallaahu Álayhi Wasallam) followed his carnal desires, he would have married all virgins and changed them in short periods of time. Since the polygamous marriages of Rasulullah (Sallallaahu Álayhi Wasallam) was by the order of Allah, therefore, the wisdom of that order cannot be questioned nor comprehended.
However, according to our limited understanding, the wisdom underlying the polygamous marriages of Rasulullah (Sallallaahu Álayhi Wasallam) was:

1. Since Rasulullah (Sallallaahu Álayhi Wasallam) came as a teacher to mankind, there are many avenues of a person's domestic life which had to be conveyed to the Ummah. It was the many wives of Rasulullah (Sallallaahu Álayhi Wasallam) who had the knowledge of these aspects and fulfilled their responsibility by conveying the teachings of Rasulullah (Sallallaahu Álayhi Wasallam) to the Ummah. Consider the following: Áaisha (Radhiallaahu Ánha) alone narrated approximately 2210 Ahaadith with regard to different laws, character, ettiquettes, etc. The narrations of Hadhrat Umme Salma (Radhiallaahu Ánhu) totals up to 378. Hafiz ibn Qayyim (RA) mentions that if the Fataawa of Hadhrat Umme Salma (RA) had to be gathered which she gave after the demise of Rasulullah (Sallallaahu Álayhi Wasallam), then the need would arise to compile an entire book. The total students of Áaisha (Radhiallaahu Ánha) are approximately 200 and she taught Deeni knowledge for 48 years consecutively after the demise of Rasulullah (Sallallaahu Álayhi Wasallam).

2. The mission of Rasulullah (Sallallaahu Álayhi Wasallam) was to convert people and propagate Islam. By marrying one woman, her entire tribe had accepted Islam. This was done by virtue of marrying that woman.

3. Rasulullah (Sallallaahu Álayhi Wasallam) had to transform the evils of the society by practice. The people shunned marrying widows especially if they already had children from their previous husbands. Rasulullah (Sallallaahu Álayhi Wasallam) married a widow and thereby changed the wrong ideology of the people. Likewise, he reformed the society that abused the orphans by caring for the orphans of the women he married.

These are but just a few wisdoms of the polygamous marriages of Rasulullah (Sallallaahu Álayhi Wasallam).