The striking of the breast is an ancient symbol of sorrow and contrition in both a religious and cultural sense. Luke describes the people of Jerusalem “beating their breasts” after seeing what had been done to Jesus, “And all the multitudes who assembled to see the sight, when they saw what had taken place, returned home beating their breasts.” (Luke 23:48)
Also in Luke, we hear the parable of the Pharisee and the tax collector, “But the tax collector, standing far off, would not even lift up his eyes to heaven, but beat his breast, saying, ‘God, be merciful to me a sinner!’” (Luke 18:13) There are also many examples of this show of sorrow in the Old Testament.
St Jerome remarked that the reason we strike our chest, rather than any other body part, is because the heart is the seat of all desires and it’s our desire to do our own will that separates us most from the will of God. In recognizing that the heart needs cleansing, by God, we are acting out the words of King David in
Psalm 51, “Create in me a clean heart, O God, and put a new and right spirit within me.” (Psalms 51:10)
In the present rite of the Mass (since the reforms of the Second Vatican Council), striking the breast is called for within the context of the first form of rite of penance at the beginning of Mass when the “I confess” is used, at the words, “through my fault, through my fault, through my most grievous fault,” and
by the priest when he uses the Roman canon (Eucharistic Prayer 1) at the words “though we are sinners.”
Before the reforms of the Second Vatican Council, it was also customary to do so at the “Lamb of God,” and at the “Lord, I am not worthy.” This practice is no longer in the rubrics for the Mass. If we ask whether the gesture of striking one’s breast at the Lamb of God is “appropriate” (rather than just a current liturgical norm), it may be. For it is a gesture subject to several symbolic meanings that go beyond the strictly penitential.
The same could be said about the custom, still common in places, of striking the breast when the bell is rung at the consecration. Here the gesture does not just express unworthiness but also devotion and the realization that one is in the presence of a great mystery. In Italy, such small acts of personal devotion realized by some members of the faithful are generally left undisturbed. To enforce a rigid uniformity in
areas where the Church has made no prescription would not seem to have any pastoral benefit.
There is a difference in the situation of catechists, who, while preparing children for Mass, should generally limit themselves to explaining the universal responses and gestures of the liturgy as well as the most common prayers of preparation and thanksgiving for before and after Mass, and that of parents and
other family members who are free to inculcate other devotional expressions and attitudes that do not contradict the general norms.
(Sources: nowthatimcatholic.com; EWTN)
Read more in the “Why Do We Do That?” series from Deacon Mike Fritz.