WSC Q.75: What is forbidden in the eighth commandment?
The eighth commandment forbiddeth whatsoever doth or may unjustly hinder our own or our neighbour’s wealth or outward estate. (Prov. 21:17, Prov. 23:20–21, Prov. 28:19, Eph. 4:28)
WLC Q.142: What are the sins forbidden in the eighth commandment?
The sins forbidden in the eighth commandment, besides the neglect of the duties required, (James 2:15–16, 1 John 3:17) are, theft, (Eph. 4:28) robbery, (Ps. 62:10) man-stealing, (1 Tim. 1:10) and receiving any thing that is stolen; (Prov. 29:24, Ps. 50:18) fraudulent dealing, (1 Thess. 4:6) false weights and measures, (Prov. 11:1, Prov. 20:10) removing landmarks, (Deut. 19:14, Prov. 23:10) injustice and unfaithfulness in contracts between man and man, (Amos 8:5, Ps. 37:21) or in matters of trust; (Luke 16:10–12) oppression, (Ezek. 22:29, Lev. 25:17) extortion, (Matt. 23:25, Ezek. 22:12) usury, (Ps. 15:5) bribery, (Job 15:34) vexatious law-suits, (1 Cor. 6:6–8, Prov. 3:29–30) unjust inclosures and depopulations; (Isa. 5:8, Micah 2:2) ingrossing commodities to enhance the price; (Prov. 11:26) unlawful callings, (Acts 19:19,24–25) and all other unjust or sinful ways of taking or withholding from our neighbour what belongs to him, or of enriching ourselves; (Job 20:19, James 5:4, Prov. 21:6) covetousness; (Luke 12:15) inordinate prizing and affecting worldly goods; (1 Tim. 6:5, Col. 3:2, Prov. 23:5, Ps. 62:10) distrustful and distracting cares and studies in getting, keeping, and using them; (Matt. 6:25,31,34, Eccl. 5:12) envying at the prosperity of others; (Ps. 73:3, Ps. 37:1,7) as likewise idleness, (2 Thess. 3:11, Prov. 18:9) prodigality, wasteful gaming; and all other ways whereby we do unduly prejudice our own outward estate, (Prov. 21:17, Prov. 23:20–21, Prov. 28:19) and defrauding ourselves of the due use and comfort of that estate which God hath given us. (Eccl. 4:8, Eccl. 6:2, 1 Tim. 5:8)