Just when the earliest collections, found in iii.-xli. and li.-lxxii., were made is a comparatively unimportant yet difficult question to decide. Probably the rebuilding of the temple in 516 B.C. was one of the great incentives. The example of the Babylonians, who possessed a large and rich psalm literature, may also have exerted an indirect influence. At least it is certain that the guilds of temple singers and the song service became increasingly prominent in the religious life of the Jewish community which grew up about the restored temple. The presence of alphabetical psalms, as, for example, ix., x., xxv., xxxiv., xxxvii., in the earliest collection suggests also the leisure of the exile. The historical background of many of these psalms is clearly the exile and the long period of distress that followed. They voice the experiences of the poor, struggling band of the pious, who, living in the midst of oppressors, found in Jehovah alone their refuge and their joy. Some of these psalms also reflect the prophetic teachings of Jeremiah (_e.g._, xvi., xxxix) and of Isaiah xl.-lxvi. In general their attitude toward sacrifice is that of the prophets: For thou desirest not sacrifice; Else would I give it. Thou delightest not in burnt offering. The sacrifices of God are a broken spirit; A broken and a contrite heart, O God, thou wilt not despise. Religion is defined in the terms of life and acts. Ceremonialism has not yet cast its chilling influence over the heart of the nation. Therefore the earliest collections may, with considerable assurance, be assigned to a date not later than the days of Nehemiah (about 400 B.C.). [Sidenote: _Later collections_] Psalms xlii.-l. and lxxiii-lxxxiii. constitute a collection of Levitical hymns. If we may follow the indications of their superscriptions, they consist of two originally distinct groups, the one, xlii.-xlix., associated with and possibly at first collected and preserved by the post-exilic guild of temple singers, known as the sons of Korah, and the other, l., lxxiii.-lxxxiii., similarly attributed to Asaph, the guild of temple singers, mentioned first in the writings of the Greek period. In these two groups the priests and Levites and the liturgy are prominent. Psalms lxxxiv.-lxxxix. constitute a short Levitical supplement. The remainder of the Psalter is also made up of originally smaller collections, as, for example, the Psalms of Ascent or the Pilgrim Psalms (cxx.-cxxxiv.), and the Hallelujah Psalms (cxi.-cxiii. and cxlvi.-cl.). Some of the latter come perhaps from the Jews of the dispersion. Each collection appears to represent a fresh gleaning of the same or slightly different fields, incorporating ancient with contemporary psalms, and, as has been noted, not infrequently including some already found in earlier collections. [Sidenote: _Completion of the Psalter_]