Through the prophet Nathan, God confronts King David over grave sins: adultery and murder.  The guilty sovereign responds by confessing his sin to the prophet and to God.  Then he humbles himself by exchanging his royal raiment for humble sackcloth, and for a week he lies on the ground and refuses all food (see 2 Sm 12:13-17).

David is performing penance in his deep grief for his wrongdoing.  His attitudes and behavior illustrate how genuine penance includes both an interior and an exterior aspect.

Interior penance is a conversion of the heart, a turning away from sin and toward God (see Dt 4:29; Jos 24:23).  It involves the penitent’s intention to change his life because he hopes in God’s mercy.  We see David’s change of heart reflected in his prayer of repentance on this occasion, recorded in Psalm 51.

External acts of penance, as David demonstrates, include such actions as fasting, prayer, and giving to those in need.  These behaviors can have several purposes: demonstrating the penitent’s intention to change; detaching him from the things he loves too much; drawing him closer to God; repairing some of the damage caused by his sin; and participating in the reparation to God (satisfaction) for sin made by Christ through his death on the cross.

David’s acts of penance are self-imposed, but Scripture shows us that sometimes God himself imposes penances on the guilty — some sort of labor or adversity, often connected to the natural consequences of the sin, that can serve a redemptive purpose if the sinner responds in the right way.  For example, the disobedient Israelite people are forced to wander in the desert for forty years (see Nm 14:26-35).  St. John the Baptist’s father, Zechariah, is temporarily struck mute when he won’t believe God’s message to him through an angel (see Lk 1:20, 62-64).

Voluntary penance is at the heart of the seasons of Lent and Advent, when Catholics traditionally make at least small sacrifices in the hope of becoming more like our Lord.  In the sacrament of Reconciliation, the priest assigns a penance on God’s behalf to help the penitent grow in holiness.

Related Scripture:

Texts Cited: Nm 14:26-35  •  Dt 4:29  •  Jos 24:23  •  2 Sm 12:13-17  •  Ps 51  •  Lk 1:20, 62-64
General: Ex 32:15-20  •  Nm 5:5-7; 14:19-23  •  Is 58:6-7  •  Jl 1:13-14  •  Jon 3:1-10  •  Zech 7:5-10  •  Mt 6:16-21; 10:38; 16:19, 24; 18:18  •  Lk 18:9-14  •  Jn 20:23  •  Rom 8:13, 17  •  1 Cor 5:1-5  •  2 Cor 4:10; 11:23-30  •  Gal 6:1  •  Phil 3:10  •  Col 1:24
Catechism of the Catholic Church: 953  •  1420-1498  •  2043