Proverbs 25:18

Here, 1. The sin condemned is bearing false witness against our neighbour, either in judgment or in common conversation, contrary to the law of the ninth commandment. 2. That which it is here condemned for is the mischievousness of it; it is in its power to ruin not only men's reputation, but their lives, estates, families, all that is dear to them. A false testimony is every thing that is dangerous; it is a maul (or club to knock a man's brains out with), a flail, which there is no fence against; it is a sword to wound near at hand and a sharp arrow to wound at a distance; we have therefore need to pray, Deliver my soul, O Lord! from lying lips, Psa 120:2.

Cross-references: Ps 120:2