"maskil" (maschil), meaning "enlightened" or "wise", because they impart wisdom. Most notable of these is Psalm 142 which is sometimes called the "Maskil of David"; others include Psalm 32 and Psalm 78. A special grouping and division in the Book of Psalms are fifteen psalms (Psalms 120–134) known in the construct case, shir ha-ma'aloth (= "A Song of Ascents", or "A Song of degrees"), and one as shir la-ma'aloth (Psalm 121). According to Saadia Gaon, these songs differed from the other psalms in that they were to be sung by the Levites in a "loud melody" (Judeo-Arabic: ). Every psalm designated for Asaph (e.g. Psalms 50, 73–83) was sung by his descendants while making use of cymbals, in accordance with 1 Chronicles 16:5. Every psalm wherein is found the introductory phrase "Upon Mahalath" (e.g. Psalms 53 and 88) was sung by the Levites by using large percussion instruments having wide and closed bezels on both sides and beaten with two wooden sticks. Later interpretation and influence Overview Individual psalms were originally hymns, to be used on various occasions and at various sacred sites; later, some were anthologised, and might have been understood within the various anthologies (e.g., ps. 123 as one of the Psalms of Ascent); finally, individual psalms might be understood within the Psalter as a whole, either narrating the life of David or providing instruction like the Torah. In later Jewish and Christian tradition, the psalms have come to be used as prayers, either individual or communal, as traditional expressions of religious feeling. Commentaries Many authors have commented on the psalms, including: Hilary of Poitiers Augustine of Hippo Saadia Gaon Thomas Aquinas John Calvin Emmanuel (pseudonym), Jewish Commentary on the Psalms. Use in Jewish ritual Some of the titles given to the Psalms have descriptions which suggest their use in worship: Some bear the Hebrew description shir (; Greek: ). Thirteen have this description. It means the flow of speech, as it were, in a straight line or in a regular strain. This description includes secular as well as sacred song. Fifty-eight Psalms bear the description mizmor (; ), a lyric ode, or a song set to music; a sacred song accompanied with a musical instrument. Psalm 145 alone has the designation tehillah (; ), meaning a song of praise; a song the prominent thought of which is the praise of God. Thirteen psalms are described as maskil