Who was the author? With the Old and New Testaments we hold that Moses was Divinely inspired to write the book, and, without denying that Divine inspiration, we allow that others later might have made minor edits.
What is the book? Exodus is the account of God's delivering His people from slavery, as He had promised He would, so that they can worship Him and live free as His people. We especially see the things Exodus describes not only as historical events but also as things that point to God's greater deliverance of us from our slavery to sin so that we can worship Him and live free as His people.
Where was it written? As with Genesis, we are not told, but the book of Exodus most likely was written in the desert of the Sinai peninsula.
When was it written? The 40-year wanderings in the desert is most likely when the book of Exodus was completed, and, as with Genesis, we estimate those wanderings took place between 1446-1406 B.C.
Why? Very few books of the Bible give a specific purpose statement for their being recorded, but I think we can safely say that the book's historical and legal material serve the purposes of both law and Gospel, primarily showing us that we are sinners and what God has done about our sin, respectively.
How? The legal material is there to curb gross sin, make us realize that we are sinful, and to describe our lives after we have been redeemed by God. The historical material shows God's great act of deliverance and points us to the even greater act of deliverance accomplished through Jesus Christ (Luke 9:31 refers to Jesus' work in Jerusalem as an "exodus").
For further reading on the book of Exodus:
- Keil, C.F. and F. Delitzsch. Biblical Commentary on the Old Testament, Volume II, The Pentateuch, translated by James Martin and published in one volume with the other two on the Pentateuch. Grand Rapids, Michigan: William B. Eerdmans Publishing Company, reprinted May 1986. (The section dealing with Exodus, "The Second Book of Moses", runs 260 pages. After my study Bible, this is what I turn to next, but it is a somewhat harder to use more-scholarly commentary.)
- Kretzmann, Paul E. Popular Commentary of the Bible: The Old Testament, Volume I, The Historical Books of the Old Testament: Genesis to Esther. St. Louis: Concordia Publishing House, 1923. (Like our Grace library, I have this volume on my shelf, and, although I didn't pull it down at all while blogging on Exodus, I would think you would find its 74 pages on Exodus somewhat helpful and generally accessible. In his commentary, Dr. Kretzmann often quotes Martin Luther, but I don't immediately see any such quotations on the pages dealing with Exodus, although I do see a quotation from the Keil commentary I list above.)