Why is the book of Psalms divided into five books?

Answer

The book of Psalms is the lengthiest book in the Bible, containing 150 “chapters”—more accurately referred to as “psalms” or “songs.” Psalms is segmented into five books:

Book 1: Psalms 1—41

Book 2: Psalms 42—72

Book 3: Psalms 73—89

Book 4: Psalms 90—106

Book 5: Psalms 107—150

The reason for Psalms being divided into five books is uncertain. Some sources, including Jewish Midrash traditions, propose that the five-fold division is rooted in the five books of the Torah (Genesis to Deuteronomy). The division of Psalms is not based on authorship or chronology, as multiple authors contributed to Psalms, and their individual songs are interspersed throughout the different collections.

David is credited as the author of 73 psalms, Asaph of 12, and the sons of Korah of 11. Other psalms were penned by Solomon, Heman the Ezrahite, Ethan the Ezrahite, and Moses (Psalm 90). The oldest existing copy of Psalms is from the Dead Sea Scrolls dating back to approximately the first century AD. This copy reveals that the division into five books dates back to at least that period and likely even earlier.

It is highly probable that Ezra and/or other Jewish religious leaders arranged the Psalms in their current order during Ezra’s lifetime in the fourth century BC. Interestingly, Psalms was among the most popular writings found among the Dead Sea Scrolls, with thirty scrolls containing all or parts of the book. Overall, Psalms is the Old Testament book with the highest number of Hebrew manuscripts available for study, indicating its enduring popularity among both Jews and Christians.

Each of these five books or sections of Psalms concludes with a doxology or a song of praise. The final verse of each concluding psalm contains either “Praise the Lord!” or “Amen.” For instance, the closing verse of Psalm 41 reads: “Praise be to the Lord, the God of Israel, / from everlasting to everlasting. / Amen and Amen.”

Psalm 150, the last psalm, acts as the appropriate concluding doxology, ending with the phrase, “Let all that has breath praise the Lord. / Praise the Lord.”