The Westminster Larger Catechism

Answer: The duties required in the eighth commandment are, truth, faithfulness, and justice in contracts and commerce between man and man; rendering to everyone his due; restitution of goods unlawfully detained from the right owners thereof; giving and lending freely, according to our abilities, and the necessities of others; moderation of our judgments, wills, and affections concerning worldly goods; a provident care and study to get, keep, use, and dispose these things which are necessary and convenient for the sustentation of our nature, and suitable to our condition; a lawful calling, and diligence in it; frugality; avoiding unnecessary lawsuits and suretyship, or other like engagements; and an endeavor, by all just and lawful means, to procure, preserve, and further the wealth and outward estate of others, as well as our own.