"Last week's scripture reading in my church was Deuteronomy 34. In the passage Moses dies and is buried. My question, if Moses wrote the book of Deuteronomy, how did he write about his death?"
This is one of the most common questions when looking at authorship in the Bible. It seems, that since the first five books in the Bible are called the Books of Moses, there is an assumption that Moses wrote them. Nothing could be further from the truth!
For years there has been a tradition, handed down to us from well before Christianity, that Moses wrote the Pentateuch (Genesis through Deuteronomy). These books, with the exception of Genesis, really contain the story of the Israelite exodus from Egypt and the reception of the Law from God. Because in the accounts Moses is the initial receptor of the Law, and thus is credited as the Law Giver, there was an assumption that he wrote the books. Early church traditions assumed that the 34th chapter of Deuteronomy had been appended by Joshua or some other leader of Israel to bring closure to the account of Moses thus answering the question of how Moses could have written about his own death and burial in a book he authored. However, in the past hundred or so years scholars have determined that there were many authors of the Pentateuch and Moses was probably not one of them.
In past columns I've dealt with the issue of authorship of Genesis, and the same is true through the rest of the Pentateuch. At least four distinct authors are discernable within the five books. The authors are designated J, E, P, D with an editor designated R for redactor. E and J are considered to be the oldest authors of portions of the Pentateuch. The letter E stands for elohist because this author uses only the appellate Elohim for God. An example of E's writings is found in Genesis 1. J stands for yahwist (in German Jehovist, thus J not Y) because this author uses the appellate Yahweh for God this shows up as LORD in most Bibles. Genesis 2.4b-3.24 is an example of J's authorship. P stands for priestly because this author reflects the concerns primarily of the priesthood. Much of Leviticus is P. D stands for Deuteronomic which is found almost exclusively in the book of Deuteronomy. It is generally thought to be quite a late document, most likely written during the reign of Josiah (2 Kings 22-23). The writings of R are found scattered throughout the Pentateuch and generally include any passage scholars generally didn't believe fit in any of the other author's style. R is credited with taking the four document of oral/written traditions and combining them into the texts that we now have.
But did Moses write any of the Pentateuch? Most scholars would say no. However, there are a few who argue that we may have a few words of Moses' authorship in the ten commandments called the decalogue. Decalogue literally means ten words, and most scholars believe originally the ten commandments were just that ten words of commandments.
In Hebrew, single words are often translated into English as short sentences. For instance, "thou shall not murder" is a single word in Hebrew and translates literally "you not murder." There are some scholars who believe the ten commandments, in their original form, are actually the words of Moses. If this were so, then the title Law Giver, when applied to Moses, is certainly appropriate. And, since virtually all of the laws contained in the Pentateuch were derived from these original ten, and since the majority of these writings deal with the giving of the Law, then attributing these books as The Books of Moses is not out of place.
But in answer to the question, Moses didn't write about his death. He didn't write about his life nor about the wilderness wanderings either. Rather, later writers preserved these stories. But maybe, just possibly, Moses did write the best known catalog of law known to the world the ten commandments.