PENITENTIAL PSALMS. - A group of psalms (Ps. 6; 31; 37; 50; 101; 129; 142 [Vulg.]) expressing confidence in God’s infinite mercy toward the sinner and the persecuted. They formed a liturgical collection from the earliest centuries of the Church; already in use in the time of s. Agostino, they are mentioned by Cassiodoro; they were apparently commented upon by s. Gregorio Magno. The series of penitential psalms was recited on the Fridays of Lent after Lauds, on Ash Wednesday for the dismissal of penitents, and on Holy Thursday for their reconciliation. It forms part of the prayers for Extreme Unction, for the consecration of churches, the blessing of cemeteries, and the blessing of the abbot. It is prescribed as a penance for clerics promoted to the tonsure and to Minor Orders.
Considered in itself, the series of penitential psalms is not a homogeneous group. It includes psalms strictly penitential in character (6; 37; 50; 129), psalms of lamentation (101; 142), and a wisdom psalm (31). Yet the character they have in common explains the function they received in Christian liturgy. Giorgio Castellino