The book of Psalms is the first book of Kethuvim, or Writings-probably because of its size and significance and also perhaps because it was the first book in Kethuvim to become authoritative. Psalms is a collection, actually a collection of collections, of poetic prayers. The origin of most of these poetic prayers is lost in obscurity, but they were pre­served because they were likely used liturgically in ancient Israel, certainly in the Second Temple and in some cases perhaps in the First Temple era.