The third book (1xxiii.-1xxxix.) consists chiefly of Aasph's psalms, but comprises apparently two smaller collections, the one Asaphitic (1xxiii. Ixxxiii.), the other mostly Korahitic (lxxxiv. lxxxix.) The collector of this book had no in tention to bring together songs written by David, and therefore he put the above notice at the end of the second book (see De Wette's Psalnzen, Einlei lung, p. 21). The date of this collection must be as late as the return from Babylon, for Ps. lxxxv. implies as much.
Thefourth book (xc.-cvi.) and the fifth (cvii.-GL) are made up chiefly of anonymous liturgic pieces, many of which were composed for the service of the second temple. In the last book we have the Songs of Degrees (cxx.-cxxxiv.), which seem to have been originally a separate collection. The five books may, with some propriety, be thus dis tinguished : the first Davidic, the second Korahitic, the third Asaphitic, and the two others Liturgic.
In the mode of dividing and numbering the Psalms, some Hebrew MSS. vary from the printed text. In some, Ps. i. and ii. are given as one, the first being reckoned as only introductory ; which accounts for the various reading in Acts xiii. 33.
So also Ps. xlii. and xliii. are sometimes joined into one, as they evidently ought to be. In the Septuagint also, which the Vulgate follows, the arrangement varies from the common order, for it joins Ps. ix. and x. together, and thus its number ing falls one behind the Hebrew as far as Ps. cxlvii., which it cuts into two at ver. 12, and thus returns to the common enumeration. There is also in the Sept. an apocryphal psalm, numbered cli., on David's victory over Goliath.
Various classifications of the Psalms have been proposed (Carpzov, liztraductio, etc., ii. 132-134). Tholuck would divide them, according to the mat ter, into songs of ,praise, of thanksgiving, of com plaint, and of instruction. De Wette suggests another method of sorting them (Einleitnng, p. 3), into—I. Hymns (t6riri in the proper sense), as viii. xviii. ; 2. National Psalms, as lxxviii. cv. ; 3. Psalms of Zion and the Temple, as xv. xxiv. ; 4. Psalms respecting the King, as ii. cx. ; 5. Psalms of complaint, as vii. xxii. ; and 6. Religious Psalms, as xxiii. xci. It is obvious, however, that no very accurate classification can be made, since many are of diversified contents and uncertain tenor.