this was posted to me by:Al kashmiri(jazakAllah)
Bismillaah,
As-salaamu `alaykum warahmatullaahi wabarakaatuh.
The Messenger sal-Allaahu `alayhi wasallam was the best in fulfilling the commands of the Qur'aan amd abstaining the prohibitions. He was the best of mankind in every aspect, in worship, moderation, fear of Allaah, justice and every other righteous quality.
As for the command in Suraah An-Nisaa to marry 2, 3 or 4 if you are able to, then this refers to the general Muslims, that they are allowed to marry up to 4 wives at once. However, the Messenger of Allaah was not included in this command, this command is to all the believers other than him.
So the Messenger sal-Allaahu `alayhi wasallaim had many wives, from them Khadija, Sawdah, `Aa'ishah, Safiyyah, Umm Habibah, Hafsa, Juwairiyah, Maymunah, Zaynab bint Jahsh, Zaynab bint Khuzaymah and Umm Salamah, may Allaah be pleased with them all, for they are the Mothers of the Believers.
If you confused as to why the Messenger of Allaah married so many women, then reasons include to unite and improve relations with tribes, to spread the message of Islaam as well as other such reasons. So the Messenger of Allaah, sal-Allaahu `alayhi wasallam married Safiyyah who was a Jew I believe, but by doing so he, sal-Alaahu `alayhi wasallam established links with her tribe and Islaam was able to spread amongst them, and they probably felt proud/happy knowing that one of their tribe members was married to a Prophet of Allaah. Likewise by marrying Hafsah, he sal-Allaahu `alayhi wasallam became related to his dear companion, the Ameer of the believers `Umar Ibn Al-Khattaab, may Allaah be pleased with him. So their already strong ties had been reinforced by this.
I can't find any scholarly information on this topic right now, but inshaa' Allaah I hope that if you look up the ayah (verse) on this subject in the Tafseer (explanation/exegis of the Qur'aan) of Imaam Ibn Katheer, you should find more information.
I hope this answers your question.
Wa`alaykum us-salaam.