Comprised of Psalms 107-50, the Psalter’s final book appears to have been compiled after Israel’s return from exile. Beginning by affirming God’s unfailing love and faithfulness and calling Israel to thank and praise God for his greatness and love, this book covers a whole range of topics related to the life of faith. It contains a majesterial A-to-Z prayer of someone focused on hearing and obeying God’s word in Psalm 119, plus 15 psalms of ascent, sung by pilgrims to Jerusalem. It includes lament, imprecation, royal, and Zion psalms. However, worship predominates, as the book closes with five psalms of praise that build to a crescendo.
Its compiler(s) organized the Psalter into five books, making it correspond to the five books of Moses’ law. Among other things, this was meant to give the Psalms the same sort of gravity in ancient Israel that the Torah held.