Speaking degradingly of someone to another appeals to our self of self-worth and self-importance. We, therefore, partake of slander all to easily. But slander can easily be categorised under “violent crimes”. Just consider the parallel statements in Psalm 140:11
Let not the slanderer be established in the land;Psalm 140:11 (ESV)
let evil hunt down the violent man speedily!
It is a fool who secretly hates someone and resorts to slander to destroy him (Pro 10:18). Slandering another aims at gaining the trust of the confidant, but in reality proves the untrustworthy character of the slanderer (Pro 11:13). Even the closest of friends can be torn apart by slander (Pro 16:28).
Personally it is wise to disassociate from slanderers (Pro 20:19). A truly just government will condemn slander (Ps 101:5). The true worshipper of Psalm 15 is a man who “does not slander with his tongue” (Ps 15:3).
So when you gather for a visit with another, consider what you say about those not present. Speak for the building up of one another, and do not tear each other down.
Let no corrupting talk come out of your mouths, but only such as is good for building up, as fits the occasion, that it may give grace to those who hear. And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.Ephesians 4:29-30 (ESV)