Acrostic poems, i.e. poems in which initial letters recurring at regular intervals follow some definite arrangement, occur to the number of 14 in the OT; another instance is Sir 51:13-30. All these are of a simple type, and are so planned that the initials recurring at fixed intervals follow the order of the Hebrew alphabet; thus the first section of the poem begins with the first letter of the Hebrew alphabet, aleph; the second with the second letter, beth; and so on down to the twenty-second and last letter, taw. The interval between the several letters consists of a regular number of lines. In Ps 111; 112 this interval is one line; in Ps 25; 34; 145; Pr 31:10-31, Sir 51:13-30, and in the fragment, which does not clearly extend beyond the thirteenth letter, contained in Na 1, the interval is 2 lines; in La 4 it is 2 longer lines, in chs. 1 and 2 it is 3 longer lines; in Ps 9; 10 (a single continuous poem), and in Ps 37, it is 4 lines. In La 3, where the interval between each successive letter of the alphabet is 3 long lines, each of each set of three lines begins with the same letter; and similarly in Ps 119, where the interval is 16 lines, each alternate line within each set of 16 begins with the same letter.

Certainly in La 2; 3; 4, and, according to the order of the verses in the Septuagint, in Pr 31, probably also in Ps 34 (where the sense seems to require the transposition of Ps 34:16 and Ps 34:15) and in Ps 9, the sixteenth and seventeenth letters of the Hebrew alphabet occupy respectively the seventeenth and sixteenth places in the acrostic scheme. The reason for this is unknown.

Comparatively few of these poems have come down to us intact. They have suffered from accidental errors of textual transmission, and probably also from editorial alterations. In some cases an entire strophe has dropped out of the text; thus the sixth strophe (of 2 lines) has fallen out between Ps 34:6-7, and the fourteenth between Ps 145:13-14, though in the latter case it still stood in the Hebrew MS from which the Greek version was made. Occasionally lines have been inserted, as, apparently, in more than one place in Ps 37, and in Na 1:2. But such corruption of the text is really serious only in Ps 9 f., Na 1, and Sir 51:13-30.

The earliest of these fifteen poems are probably La 2; 4, which may have been written in the earlier half of the 6th cent. b.c.; but the custom of writing such poems may have been much more ancient. Perhaps the latest of the poems is Sir 51:13-30 (about b.c. 180), but the Jews continued to compose such poems long after this.

The English reader will find the strophes clearly distinguished, and the initial Hebrew letters with their names in English letters indicated, in the RV of Ps 119. Unfortunately the RV does not give the initials in the other poems; but they will be found, in the case of the Psalms, in (for example) Kirkpatrick's Psalms (Cambridge Bible), Cheyne's Book of Psalms, Driver's Parallel Psalter. For La 2; 4 see Expositor, 1906 (April) [G. A. Smith]; for Na 1, Expositor, 1898 (Sept.), pp. 207