Psalms תהילים
The hundred and fifty psalms of David — the book on which all Jewish prayer rests.
Tehilim is a hundred and fifty chapters, most headed with David's name; the Talmud says he composed the book «through ten elders», among them Adam, Malkitzedek, Avraham, Moshe and the sons of Korach. Its range is extraordinary: from «the Lord is my shepherd, I shall not want» to «my God, my God, why have You forsaken me», from gratitude to despair and back, sometimes within one psalm.
That honesty made it the central text of Jewish prayer. The psalms furnish pesukei dezimra, Ashrei, Hallel and the psalm of the day; they are said at a sick bed, in danger, at funerals and at celebrations. Many divide the book to complete it weekly or monthly.
It is the one book of the Tanakh that is often simply recited rather than studied.