In the Divine Office, the De Profundis is said every Wednesday at Compline, at Wednesday Vespers during week four, and First Vespers of Sunday in the same week. This is more than proper, as the Church certainly remembers the dead very often-even including them in the general intercessions of Vespers every day of the week. It is included among the traditional fifteen Gradual Psalms, which were included in the Roman Breviary at a relatively early date. It is also said on Second Vespers of Christmas, with its tone of longing for the coming of the Lord reaching its climax here at the end of Advent and the arrival of the Messiah. It is also said on Second Vespers of the Presentation of the Lord, recalling how Simeon waited in longing to see the Messiah, and finally “seeing the salvation which You have prepared in the sight of every people.”
The tradition of ringing a bell to remind the faithful to pray for the dead is a very ancient custom. Even predating the tradition of the Angelus Bell, the De Profundis Bell was rung to denote a time of the day to recite Psalm 130. The origin of this custom is accredited to Pope Urban II, who promoted the ringing of the De Profundis in order to pray for Christian armies in the Crusade. Later popes would grant indulgences to those who recited the psalm, even if the bell was not rung. This custom was later introduced in 1622 in churches belonging to the Dominican Order, who attribute the origin of this bell to St. Cajetan in 1546.
The Dominicans certainly had a preference for this psalm when praying for the dead. At the close of the Middle Ages, they would recite the penitential psalms after prime on feria days of three lessons. This devotion expanded to the obligatory recitation of the Office of the Dead on a daily basis. In fact, members of the Order would recite the psalm while walking from observance to observance. As a result, the area from the chapter room to the refectory was nicknamed the De Profundis.
In the modern liturgical cycle, Psalm 130 is read on the fifth Sunday of Lent in Year A, the tenth Sunday of Year B, and the first Friday of Lent, Tuesday of the 27th week of Year 1, and Thursday of the 28th week of Year 1 to name a few instances. The tenth Sunday of Year B includes a passage from Genesis depicting the fall of Adam and Eve. This “fall” is then echoed again in the psalm response that comes “out of the depths.” The gospel of that Sunday comes from Mark; every sin will be forgiven mankind and all the blasphemies men utter. When it is read on the first Friday of Lent, it is preceded by Ez 18:21-28; “If a wicked man turns away from his sins, he shall live.” It is clearly a psalm which has many uses for the Church’s liturgy, including prayers for the dead, for the penitent, and for the thankful and repentant sinner.