Who Wrote the Book of Genesis?

Moses is traditionally considered the author of Genesis. But for over two centuries, one of the most contested questions in biblical scholarship has been “Who wrote the Book of Genesis—and when?”

Genesis is the first book of the Bible, and one of the five books of the Pentateuch. Several other books of the Pentateuch include passages that mention Moses recording events and writing down what God says. The authors of the New Testament—and even Jesus himself—appear to credit Moses as the author of Genesis.

So why don’t scholars agree?

There are passages in Genesis that Moses could not have written, because they describe events that happened after his death, known as postmosaica passages. And there are others that would simply be awkward for Moses to write, which are referred to as amosaica (such as Numbers 12:4). If these passages were added later, how do we know what Moses did and didn’t write?

So the real question is: did Moses write Genesis, or not?

Renowned Old Testament scholar Tremper Longman III tackles this question in his video series on the book of Genesis. The following post is adapted from his series.

Did Moses write Genesis?

For many, the answer to this question is a matter of orthodoxy, and debates quickly become passionate. While it seems simple (the author is Moses or not), scholars don’t necessarily treat it as a yes or no question—they also have to consider that Moses may have written part of Genesis.

For some, orthodoxy simply suggests that Moses wrote the whole Pentateuch, perhaps with the exception of postmosaica passages such as Genesis 11:28 and 14:14 and amosaica passage such as Numbers 12:4.

On the other extreme are those who say that Moses wrote none of the Pentateuch, but rather the Pentateuch was composed much later than the time the Bible purported that he lived (if, in the minds of some, he lived at all).

In the following discussion, whatever we say about the Pentateuch pertains to the book of Genesis, though we will also on occasion refer specifically to the book of Genesis.

Passages that refer to Moses’ writing

Right from the start it is important to note that the Pentateuch is anonymous. Nowhere in the Pentateuch is an author named, not Moses or any other person. However, that said, a number of passages in the Pentateuch mention that Moses wrote things down.

Consider the following:

Exodus 17:14
“Then the Lord said to Moses, ‘Write this on a scroll as something to be remembered and make sure that Joshua hears it . . .’”

Exodus 24:3-4
“When Moses went and told the people all the Lord’s words and laws, they responded with one voice, ‘Everything the Lord has said we will do.’ Moses then wrote down everything the Lord had said.”

Numbers 33:2
“At the Lord’s command Moses recorded [wrote down] the stages in their journey.”

Deuteronomy 31:24
“After Moses finished writing in a book the words of this law from beginning to end . . .”

And these references are just a sample of a number of other passages that could be cited (see also Exodus 24:12; 34:28; Deuteronomy 27:3, 8; 31:19).

None of these passages concern the writing of the book of Genesis.

Certainly the passages that speak of Moses writing things down do not claim that Moses wrote the entirety of the Pentateuch, but they do imply that Moses wrote material that was incorporated into the Pentateuch.

With this in mind, we turn now to references to the “book of the law of Moses” or “the book of Moses” (with variants) found in biblical books that follow the Pentateuch.

Here are just a few examples:

Joshua 1:7-8a
“Be strong and very courageous. Be careful to obey all the law my servant Moses gave you; do not turn from it to the right or to the left, that you may be successful wherever you go. Keep this Book of the Law always on your lips . . .”

2 Chronicles 25:4
“Yet he did not put their children to death, but acted in accordance with what is written in the Law, in the Book of Moses, where the Lord commanded . . .”

Nehemiah 13:1
“On that day the Book of Moses was read aloud in the hearing of the people . . .”

These references to the Book or Law of Moses are not necessarily, and until the postexilic period are unlikely, indicating the Pentateuch in its final form as we know it, but still they attest to some body of writing that was connected to the figure of Moses.

The New Testament appears to consider Moses the author

When we come to the New Testament, however, these references are more likely to refer to the final form of the Pentateuch. They still do not necessarily mean that Moses wrote every word, but they do imply a belief that Moses had an integral connection with the composition of the Pentateuch.

In the New Testament, when quoting the Pentateuch, people often spoke of Moses being the author. For example, the disciples, referring to Deuteronomy 24:1–4, questioned Jesus, “ ‘Why then,’ they asked, ‘did Moses command that a man give his wife a certificate of divorce and send her away?’ ” (Matthew 19:7).

Jewish leaders asked Jesus a question based on Deuteronomy 25:5–10 by saying, “‘Teacher,’ they said, ‘Moses told us that if a man dies without having children, his brother must marry the widow and raise up offspring for him’ ” (Matthew 22:24).

Jesus himself, quoting the fifth commandment (Exodus 20:12; Deuteronomy 5:16) and a case law (Exodus 21:17; Leviticus 20:9), said, “For Moses said, ‘Honor your father and mother,’ and ‘Anyone who curses their father or mother is to be put to death” (Mark 7:10). For other New Testament references see Mark 12:26; John 1:17, 5:46, 7:23.

In light of the references to Moses’ writing in the Pentateuch and the New Testament citations of the Pentateuch that associate Moses with its composition, it seems reasonable to affirm that the origins of the Pentateuch are connected to this great biblical figure.

What about postmosaica passages?

But to say that the composition, even the origins, of the Pentateuch is to be associated with Moses certainly does not mean he wrote every word. Traditional approaches to this question acknowledge that Moses did not write the entirety of the Pentateuch when they point to a so-called postmosaica.

Postmosaica are passages that had to be written after the death of Moses, and of course, the most obvious postmosaica is the account of his death in Deuteronomy 34. There are postmosaica in the book of Genesis as well.

While Ur is an ancient city predating Moses, the reference to Ur of the Chaldeans (see Genesis 11:31) is a postmosaica since the Chaldeans were an Aramaic-speaking tribe that lived in the first millennium BC, long after the death of Moses.

In Genesis 14:14 the narrator reports that Abram chased the four ancient Near Eastern kings who kidnapped Lot “as far as Dan.” This reference to the city of Dan is a postmosaica because this city, earlier called Laish, was not named Dan until the time of the Judges (see Judges 18), and of course the name derived from the tribe of Dan, named after Jacob’s son Dan, Abraham’s great grandson.

Do we really know what Moses did and didn’t write?

No. While some people believe that Moses wrote everything in the Pentateuch except a handful of postmosaica, the postmosaica may only be the tip of the iceberg. These postmosaica establish a principle that later inspired editors/redactors can contribute to the writing of the Pentateuch.

In Genesis, the narrative speaks of events that take place long before the birth of Moses. It is interesting that Moses is never mentioned in the book even as the person writing things down.

Instead, we encounter a formula that appears eleven times in the book (2:4; 5:1; 6:9; 10:1; 11:10, 27; 25:12, 19; 36:1, 9; 37:2). This formula is introduced by the words elleh toledot and a person’s name, “This is the account of [name].” These sections indicate the use of oral and/or written sources (see 5:1) for the writing of the book of Genesis.

Taking seriously the indications within the Pentateuch itself, along with the post-pentateuchal references to the Book/Law of Moses, one might conclude that the Pentateuch finds its origins in Moses, who used other sources particularly in the writing of Genesis.

The postmosaica indicate that there were also editorial additions. These additions may only be the most obvious examples of textual material added after the time of Moses and we cannot determine precisely what was authored by Moses or added by later inspired editors.

So, ”Who wrote Genesis?” We’ll likely never know with absolute certainty. But based on the evidence available, it’s fair to attribute its origins to Moses.

Learn more in Tremper Longman's video series on the book of Genesis ›