Overview highlights structure and significance of biblical Book of Psalms

The Book of Psalms, comprising 150 poems, is the third-longest book in the Bible. Most translations divide the psalms into five sections, each ending with a doxology: 1-41, 42-72, 73-89, 90-106, and 107-150.

Authorship of the psalms is attributed to several figures. David is credited with writing 73 psalms, Moses with one, Solomon with two, and other authors are named for several more. However, the true identity of many authors remains uncertain; some names may be pseudonyms. There are also 49 psalms without known authors.

Superscriptions appear at the beginning of 116 psalms. These brief introductions often include information such as the author’s name or musical instructions. For example, Psalm 54’s superscription reads: “For the Leader. On stringed instruments. A maskil of David, when the Ziphites came and said to Saul, ‘David is hiding among us.’” Superscriptions suggest that these poems were used in Jewish liturgical worship.

A recurring but unexplained feature in some psalms is the Hebrew word “selah,” which appears 71 times. Scholars have not determined its exact meaning; it may be a musical or liturgical direction such as a pause or an instruction to praise.

While it is difficult to categorize every psalm by type or topic, lamentation is considered the most common theme—about 65 psalms express lament. Other types include praise or thanksgiving, royal themes, wisdom literature, and imprecatory content directed against enemies.

Nine psalms are acrostic poems structured so that each stanza begins with consecutive letters of the Hebrew alphabet. Psalm 119 exemplifies this form; it consists of eight-line stanzas where every line within a stanza starts with the same letter.

Psalm 23 (“The Lord is my shepherd…”) remains perhaps the best-known psalm. Psalm 90 may be among the oldest and is attributed to Moses before the Exodus event. Psalm 117 holds distinction as both the shortest psalm and chapter in the Bible at just two verses long. Conversely, Psalm 88 stands out as unique for lacking a hopeful conclusion; its final verse states: “Friend and neighbor you have taken away, my one companion is darkness.”

Psalms play a central role in Catholic worship practices. Passages from them are read at every Mass and form much of the Liturgy of the Hours cycle over four weeks—during which nearly all (147 out of 150) are prayed by those observing this practice.

An additional note comes from early Greek translations: The Septuagint includes a “151st” psalm attributed to David after his defeat of Goliath but marks it as non-canonical—a status maintained by Catholic tradition.