Any point in the text might serve equally well as the beginning or the end, because in a sense the Qur’an is always complete. Whatever God has to say in response to a situation is never left unsaid; God is never at a loss for words. If there is more to come, it is not so much because God is only part way through displaying an already completed text, but rather because further situation will arise that call for direct divine address. The Qur’an presents itself not so much as a corpus completed in the past, but as the voice of God in the present.
Madigan, Daniel A. The Qur’ân’s Self Image: Writing and Authority in Islam’s Scripture. Princeton: Princeton University Press, 2001, 70.