This study analyses seven editions of the Psalterbuch, a vernacular interpretation of the biblical Psalms by the Lutheran theologian Nikolaus Selnecker (1530–1592). It tracks the transformation of the Psalterbuch across a period of sixty years, from 1563 to 1623, and it shows how the work was continually reshaped in response to shifting historical conditions and in dialogue with other works of devotional literature. The point of departure is the question of how the private character of the Book of Psalms is appropriated in early modern Lutheran biblical interpretation. In the Psalterbuch, Selnecker interprets the Book of Psalms in homilies, hymns, poems, and prayers, and the study concludes that each edition of the Psalterbuch has different devotional emphases on a spectrum between the individual and the communal. These are created not just by additions and subtractions to the content but also by shifts in typography and layout. With its focus on the material textuality of the Psalterbuch, the study contributes to ongoing scholarly conversations about Lutheran devotional literature, the diversity of sixteenth-century biblical interpretation, and possible approaches to the study of early modern privacy.