Psalms is the Bible’s songbook. Written over centuries, it was finally compiled in the form that Jesus knew, and that we also know, in the post-exilic period, that time when Zerubbabel rebuilt the Temple in Jerusalem with Ezra, Zechariah and Haggai as contemporaries. Many of the Psalms are much older, dating back before Solomon’s Temple and into the life of David, who is a primary author. In the version that gets established, there are five books (Psalm 1-41; 42-72; 73-78; 90-106; 107-150). There are reasons for these divisions, including a doxology that closes each one as well as how God is referenced. Most important, the divisions indicate particular time periods more than anything else.