Answer
The book of Exodus tells how God rescued His people from slavery in Egypt and freed them to live holy lives in a covenant with Him. Memorable parts of the story include God striking Egypt with ten plagues of judgment, Israel escaping through the parted waters of the Red Sea, and God giving Moses the Ten Commandments on Mount Sinai. Internal and external biblical evidence indicates that Moses wrote Exodus near the end of the events it describes, between 1440 and 1400 BC.
Since Moses wrote Exodus, knowing the dates of his lifetime provides a starting point for determining when the book was written. Moses lived between 1520 and 1400 BC, so the composition of Exodus occurred during that 120-year period. Additionally, Exodus includes information that can further refine the timeframe. For example, Exodus 24:4 marks when Moses began to write: “And Moses wrote down all the words of the Lord. He rose early in the morning and built an altar at the foot of the mountain, and twelve pillars, according to the twelve tribes of Israel” (ESV). This occurs after Israel crossed the Red Sea, traveled south on the Sinai Peninsula, and camped at the base of Mount Sinai. Israel’s departure from Egypt occurred when Moses was 80 years old (Exodus 7:7), so he wrote the book of Exodus during the last 40 years of his life.
Direct references supporting Moses’ authorship of Exodus during the forty years between Israel’s departure from Egypt and their entrance into the Promised Land include mentions of Moses recording events as they happened. For example, Moses is seen writing the historical record of Israel’s battle with the Amalekites in the Sinai Peninsula (Exodus 17:14), the Ten Commandments at Mount Sinai (Exodus 34:4, 27–29), and God’s revelation of the Book of the Covenant (Exodus 20:22—23:33).
Furthermore, there is an abundance of biblical evidence outside of Exodus that attributes authorship to Moses, strengthening support for the time of its composition. Sources confirming Mosaic authorship include the first passage of Joshua, where God says to Moses’ successor, “Only be strong and very courageous, being careful to do according to all the law that Moses my servant commanded you” (Joshua 1:7; also see Joshua 1:8; 8:31–32). Additionally, the historical books and the prophets also testify to Moses’ authorship (1 Kings 2:3; 2 Kings 14:6; Nehemiah 13:1; Daniel 9:11–13; Malachi 4:4). In the New Testament, the Gospels affirm Moses’ authorship of Exodus (Mark 7:10; 12:26; Luke 2:22–23; John 5:46–47; 7:19), as do the writings of Paul (Romans 10:5).
The most common argument against Moses’ authorship of Exodus, and thus the time of its composition, posits that multiple writers and editors contributed to the book’s final form hundreds of years after the events occurred. Popularized in liberal theology in Europe in the 1800s, this argument, known as the documentary hypothesis, rejects the evidence found in Exodus, as well as in other Old and New Testament books, that assign authorship to Moses. Instead, it hypothesizes that four unnamed authors contributed to the composition of Exodus approximately 600 to 800 years after Moses lived. These theoretical authors are identified by the letters J for Yahwist, E for Elohist, P for Priestly, and D for Deuteronomist—based on the names of God used in the first five books of the Bible. The documentary hypothesis has never been proved, and it remains a fanciful idea of those who discount the testimony of Jesus and the writers of the New Testament that Moses wrote Exodus and the rest of the Pentateuch.
Understanding when Moses wrote Exodus can strengthen the reader’s faith in the historical reliability of the narrative and set the stage for understanding its relevancy for today.
