CIC 708 This divine pedagogy appears especially in the gift of the Law.1 God gave the Law as a “pedagogue” to lead his people toward Christ.2 But the Law’s powerlessness to save man deprived of the divine “likeness,” along with the growing awareness of sin that it imparts,3 enkindles a desire for the Holy Spirit. The lamentations of the Psalms bear witness to this.

CIC 1456 Confession to a priest is an essential part of the sacrament of Penance: “All mortal sins of which penitents after a diligent self-examination are conscious must be recounted by them in confession, even if they are most secret and have been committed against the last two precepts of the Decalogue; for these sins sometimes wound the soul more grievously and are more dangerous than those which are committed openly.”4
When Christ’s faithful strive to confess all the sins that they can remember, they undoubtedly place all of them before the divine mercy for pardon. But those who fail to do so and knowingly withhold some, place nothing before the divine goodness for remission through the mediation of the priest, “for if the sick person is too ashamed to show his wound to the doctor, the medicine cannot heal what it does not know.”5

CIC 2056 The word “Decalogue” means literally “ten words.”6 God revealed these “ten words” to his people on the holy mountain. They were written “with the finger of God,”7 unlike the other commandments written by Moses.8 They are pre-eminently the words of God. They are handed on to us in the books of Exodus9 and Deuteronomy.10 Beginning with the Old Testament, the sacred books refer to the “ten words,”11 but it is in the New Covenant in Jesus Christ that their full meaning will be revealed.

CIC 2061 The Commandments take on their full meaning within the covenant. According to Scripture, man’s moral life has all its meaning in and through the covenant. The first of the “ten words” recalls that God loved his people first:
Since there was a passing from the paradise of freedom to the slavery of this world, in punishment for sin, the first phrase of the Decalogue, the first word of God’s commandments, bears on freedom “I am the LORD your God, who brought you out of the land of Egypt, out of the house of slavery.”12

CIC 2084 God makes himself known by recalling his all-powerful loving, and liberating action in the history of the one he addresses: “I brought you out of the land of Egypt, out of the house of bondage.” The first word contains the first commandment of the Law: “You shall fear the LORD your God; you shall serve him. .. You shall not go after other gods.”13 God’s first call and just demand is that man accept him and worship him.

CIC 2142 The second commandment prescribes respect for the Lord’s name. Like the first commandment, it belongs to the virtue of religion and more particularly it governs our use of speech in sacred matters.

CIC 2168 The third commandment of the Decalogue recalls the holiness of the sabbath: “The seventh day is a sabbath of solemn rest, holy to the LORD.”14

CIC 2169 In speaking of the sabbath Scripture recalls creation: “For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested the seventh day; therefore the Lord blessed the sabbath day and hallowed it.”15

CIC 2200 Observing the fourth commandment brings its reward: “Honor your father and your mother, that your days may be long in the land which the LORD your God gives you.”16 Respecting this commandment provides, along with spiritual fruits, temporal fruits of peace and prosperity. Conversely, failure to observe it brings great harm to communities and to individuals.

CIC 2214 The divine fatherhood is the source of human fatherhood;17 this is the foundation of the honor owed to parents. The respect of children, whether minors or adults, for their father and mother18 is nourished by the natural affection born of the bond uniting them. It is required by God’s commandment.19

CIC 2258 “Human life is sacred because from its beginning it involves the creative action of God and it remains for ever in a special relationship with the Creator, who is its sole end. God alone is the Lord of life from its beginning until its end: no one can under any circumstance claim for himself the right directly to destroy an innocent human being.”20

CIC 2331 “God is love and in himself he lives a mystery of personal loving communion. Creating the human race in his own image. .. God inscribed in the humanity of man and woman the vocation, and thus the capacity and responsibility, of love and communion.”21
“God created man in his own image. .. male and female he created them”;22 He blessed them and said, “Be fruitful and multiply”;23 “When God created man, he made him in the likeness of God. Male and female he created them, and he blessed them and named them Man when they were created.”24

CIC 2401 The seventh commandment forbids unjustly taking or keeping the goods of one’s neighbor and wronging him in any way with respect to his goods. It commands justice and charity in the care of earthly goods and the fruits of men’s labor. For the sake of the common good, it requires respect for the universal destination of goods and respect for the right to private property. Christian life strives to order this world’s goods to God and to fraternal charity.

CIC 2464 The eighth commandment forbids misrepresenting the truth in our relations with others. This moral prescription flows from the vocation of the holy people to bear witness to their God who is the truth and wills the truth. Offenses against the truth express by word or deed a refusal to commit oneself to moral uprightness: they are fundamental infidelities to God and, in this sense, they undermine the foundations of the covenant.

CIC 2514 St. John distinguishes three kinds of covetousness or concupiscence: lust of the flesh, lust of the eyes, and pride of life.25 In the Catholic catechetical tradition, the ninth commandment forbids carnal concupiscence; the tenth forbids coveting another’s goods.

CIC 2534 The tenth commandment unfolds and completes the ninth, which is concerned with concupiscence of the flesh. It forbids coveting the goods of another, as the root of theft, robbery, and fraud, which the seventh commandment forbids. “Lust of the eyes” leads to the violence and injustice forbidden by the fifth commandment.26 Avarice, like fornication, originates in the idolatry prohibited by the first three prescriptions of the Law.27 The tenth commandment concerns the intentions of the heart; with the ninth, it summarizes all the precepts of the Law.

1 Cf. Ex 19-20; Deut 1-11; 29-30.
2 Gal 3:24.
3 Cf. Rom 3:20.
4 Council of Trent (1551): DS 1680 (ND 1626); cf. Ex 20:17; Mt 5:28.
5 Council of Trent (1551): DS 1680 (ND 1626); cf. St. Jerome, In Eccl. 10, 11: PL 23:1096.
6 Ex 34:28; Deut 4:13; 10:4.
7 Ex 31:18; Deut 5:22.
8 Cf. Deut 31:9. 24.
9 Cf. Ex 20:1-17.
10 Cf. Deut 5:6-22.
11 Cf. for example Hos 4:2; Jer 7:9; Ezek 18:5-9.
12 Origen, Hom. in Ex. 8,1: PG 12, 350; cf. Ex 20:2; Deut 5:6.
13 Deut 6:13-14.
14 Ex 31:15.
15 Ex 20:11.
16 Ex 20:12; Deut 5:16.
17 Cf. Eph 314.
18 Cf. Prov 1:8; Tob 4:3-4.
19 Cf. Ex 20:12.
20 CDF, instruction, Donum vitae, intro. 5.
21 FC 11.
22 Gen 1:27.
23 Gen 1:28.
24 Gen 5:1-2.
25 Cf. 1 Jn 2:16.
26 Cf. 1 Jn 2:16; Mic 2:2.
27 Cf. Wis 14:12.