Psa 50:20 Thou sittest and speakest against thy brother; thou slanderest thine own mother's son.
Slandering is when we speak to the prejudice of another, and speak that which is NOT TRUE.
Worth and eminency are commonly blasted by slander; holiness itself is no shield from slander:
Mat 11:18 For John came neither eating nor drinking, and they say, He hath a devil.
Come and let us smite him with the tongue. A slanderer wounds another's name, and no physician can heal these wounds.
The sword doth not make so deep a wound as the tongue. The Greek word for slanderer, signifies devil.
Some think it is no great matter to belie and defame another; but know, this is to act the part of a devil.
The slanderer's tongue is a two-edged sword, it wounds two at once; while the slanderer wounds another in his name, he wounds himself in his conscience.
This is contrary to Scripture, "Speak not evil one of another" (James 4:11).
GOD takes this ill at our hands, to speak evil of others, especially such as are eminently holy, and help to bear up the honor of religion:
Were ye not afraid to speak against my servant Moses? (Numbers 12:8).
What! My servant who has wrought so many miracles-whom I have spoken with in the mount face to face...were not ye afraid to speak against him?
So will GOD say, You must take heed of this, it is a sin your nature is very prone to; and remember, it is no less sin to rob another of his good name, than to steal his goods or wares out of his shop.