Psalms 151 through 155 are not found in the Masoretic Text books of Psalms, or in rabbinic writings. A Psalm 151 was recorded in the Septuagint, whereas Psalms 152—155 were only found in some Syriac (or Christian Aramaic) Peshiṭṭa texts. For a long time, it was assumed that they were Greek compositions, either by Hellenized Jews or not by Jews at all. That all changed with the discovery of the Dead Sea Scrolls, specifically 11Q5, also known as the Great Psalms Scroll. This scroll not only included text from thirty-two psalms (in a non-standard order), but also passages from Apocryphal Psalms 154, 155, and 151, as well as sections of Ben Sira and several otherwise unknown psalmodic compositions. Here the editor has taken the Hebrew text from the Great Psalms Scroll, supplemented with Peshiṭṭa content for the worn passages, and attempted to create Masoretic-style vocalization and cantillation for these three fascinating pieces of Hebrew apocrypha, along with a new English translation.

Psalm 155 is an incomplete acrostic (the Dead Sea Scrolls text records it going from ב to נ, and the Syriac can be reconstructed to include up to פ) with similarities to petitionary psalms like Psalm 3, 22, and 143. It is unclear why it was not included in the Masoretic canon, but one can hazard a guess that it was just not familiar to the compilers.