This book examines how penitential prayers reflect literary conventions operative in the psalms of communal lament and how these conventions are at times modified in the prayers. The point of departure is the recognition that penitential prayers become well attested in Judaism after the exile. A review of prayers from Third Isaiah and the Writings indicates that in these expressions of penitence, one element is dominant: the confession of sin. This work analyzes the confession of sin and other elements common to both the penitential prayers and the psalms of communal lament. By analyzing elements that are constitutive of shared form, it becomes possible to state the literary relationship between the psalms of communal lament and the post-exilic prayers of penitence. Paperback edition is available from the Society of Biblical Literature (www.sbl-site.org).