Other than a general change of length, the Medinan Surahs being more prolonged and extensive than the Meccan ones, the character of the Surahs also changed.
http://www.hyperhistory.net/apwh/essays/cot/t1w11meccasurahmedinian.htm
The sentences are long and unwieldly so that the hearer has to listen carefully or he will miss the rhyme altogether; the language has become prose with rhyming words at intervals. The subject matter is laws, comments on public events, statements of policy, rebukes to those who did not see eye to eye with the prophet, Jews especially, and references to his domestic troubles. Here imagination is weak and stock phrases are dragged in to conceal the poverty of ideas though occasionally the earlier enthusiasm bursts out. (Tritton,
Islam, p. 16).
A voice is crying from the very depths of life and impinging forcefully on the Prophet's mind in order to make itself explicit at the level of consciousness. This tone gradually gives way, especially in the Medina period, to a more fluent and easy style as the legal content increases for the detailed organization and direction of the nascent community-state. (Rahman,
lslam, p. 30).
Yet the revelations which he received, in Mecca so passionate and overwhelming, seemed in Medina to become increasingly, though perhaps unconsciously, the result of reason and thought. (Glubb,
The Life and Times of Muhammad, p. 231).
In the earlier chapters these verses are short, just as the style is living and fiery; in the later chapters they are of lumbering length, prosaic and slow, and the rhyme comes in with often a most absurd effect. (MacDonald,
The Religious Attitude and Life in Islam, p. 31).
Yet the style of the Koran shows the change for the worse. As its sincerity, in the deepest sense of the word, seems to diminish, its subject-matter gets more and more mundane and prosaic; and with that the fire, the terseness, the rhymed beauty of the style gradually fades away into prolixity, tameness, obscurity, wearying repetitiousness. (Gairdner,
The Reproach of Islam, p. 48).
The style of the Koran, though varying greatly in force and vigour, has for the most part lost the stamp of vivid imagination and poetic fire which marks the earlier Suras. It becomes, as a rule, tame and ordinary both in thought and language. Occasionally, indeed, we still find traces of the former spirit. (Muir,
The Life of Mahomet, p. 328).
In Mecca Mohammed was weak, struggling to be accepted, often mocked at and ridiculed. He tried to appeal to the people of Mecca by being compassionate and loving. His teachings condemned violence, injustice, neglect of the poor.
However, after he moved to Medina and his followers grew in strength and number, he became a relentless warrior, intent on spreading his religion by the sword.
http://www.omegaletter.com/articles/articles.asp?ArticleID=5900
