Jewish tradition has held that Exodus was one of the five books of the Law (Lat. Pentateuch) that Moses wrote at the command of God. Internal evidence does not contradict this position. Although the book never says explicitly that Moses was its author, it does include materials that must have come from Moses himself, such as private conversations between himself and God. Furthermore, no other author is indicated.
At the same time, it must be said that along with the other books of the Pentateuch, Exodus does not betray that unity of style and development that we usually associate with a single author. This factor along with other apparent difficulties has lead many OT scholars to suppose that all five of the books had a complex compositional history, coming into their final form only sometime after the Jews' return from Babylonian exile in 539 b.c.
Conservative scholars have pointed out that these theories are based on negative assumptions concerning the possibility of divine revelation and about the historical worth of the text. In contrast, they have argued that we should not evaluate ancient literature according to the standards that are current today and have pointed out the various ways in which discoveries about the ancient Near East have supported biblical statements. Conservatives have recognized, however, that it is no disservice to the plain claims of the text to see Moses as editor rather than as author. As an editor, he may have written significant portions of the final copy (cf. Dt 31:9) and may also have used the work of other individuals, whether earlier than he or contemporary with him, to round out the whole (cf. Nu 21:14). If this is so, it solves many of the so-called problems.
In any case, it is clear that the reader is meant to read Exodus as the report of those events that were formative to Israel's existence as a nation. But it is also clear that Exodus is not to be read alone. At the outset it is to be read in the light of Genesis. Exodus begins with a reference to those who went down to Egypt with Jacob (1:1), and it is built around the implicit question of whether God is able to keep the promises of land, progeny, and name, which God had made to Abraham in the former book (e.g., 12:1-3).
By the same token, Exodus gives rise to questions that can be answered only by the succeeding book, Leviticus. As Exodus closes, it gives in great detail the structure of the worship center, the tabernacle, where God will be present in the midst of his people. But beyond generalities, Exodus does not spell out how God will meet with them nor what the implications of his presence are for them. Those issues, and others like them, are dealt with in detail in Leviticus.
Thus it is apparent that while Exodus is a unit in itself, dealing with the deliverance from Egypt and what that means, it is not intended to be read as a solitary unit. It is a part of a larger compositional whole. Modern scholarship would have us believe that this work was the result of centuries of all-but-unconscious community shaping, with certain unknown individuals giving direction from time to time. It takes much less credulity to believe that the work is that of a single great intellect working under the inspiration of God.