Hopefully in a month or so (sometime this summer) there will be a book about this and the new English translation of the Mass. Here are the opening two paragraphs of the chapter on the Penitential Act:
WHEN JESUS ENTERED Jerusalem during the week of his Crucifixion (on the day we commemorate as Palm Sunday), he went into the Temple area and “caused a scene.” He drove out the money-changers, men who “helped” Jews on pilgrimage by trading their foreign currency for the coinage used in the Temple… at a lousy exchange rate. After chastising these dishonest bankers, Jesus turned his attention to the blind and the lame, whom he healed. We commemorate – and enter into – his cleansing of the Temple and his healing of the infirm at every Mass. It is called the Penitential Act.
The purpose of the Penitential Act, in the words of the Missal itself, is to “prepare ourselves to celebrate the sacred mysteries.” To do this in honesty and sincerity before God, we must examine ourselves and admit our sin and our sinfulness, asking the Lord for His mercy. Jesus tells us to be reconciled with one another before we present our offerings and ourselves at the altar. (cf. Matt. 5:23-24) In the words of the Catechism, “the first movement of the prayer of petition is
asking forgiveness. … It is a prerequisite for righteous and pure prayer.” (
Catechism 2631) This is true both in the liturgy and in our personal prayer.
Praying the Mass: The Prayers of the People, p. 37