CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 2462–2465

2462 Giving alms to the poor is a witness to fraternal charity: it is also a work of justice pleasing to God.
2463 How can we not recognize Lazarus, the hungry beggar in the parable (cf. Lk 17:19-31), in the multitude of human beings without bread, a roof or a place to stay? How can we fail to hear Jesus: "As you did it not to one of the least of these, you did it not to me" (Mt 25:45)?
You shall not bear false witness against your neighbor.

It was said to the men of old, "You shall not swear falsely, but shall perform to the Lord what you have sworn."

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.

2465 The Old Testament attests that God is the source of all truth. His Word is truth. His Law is truth. His "faithfulness endures to all generations." Since God is "true," the members of his people are called to live in the truth.