"You shall not go about as a slanderer among your people, and you are not to act against the life of your neighbor; I am the Lord."
Leviticus 19:16

"The words of a gossip are like choice morsels; they go down to a man's inmost parts."
Proverbs 18:8 (NIV)

"He who goes about as a slanderer reveals secrets, therefore do not associate with a gossip."
Proverbs 20:19

"A gossip betrays a confidence, but a trustworthy man keeps a secret."
Proverbs 11:13 (NIV)

"A perverse man spreads strife, and a slanderer separates intimate friends."
Proverbs 16:28

"The north wind brings forth rain, and a backbiting tongue, an angry countenance."
Proverbs 25:23

"For lack of wood the fire goes out, and where there is no whisperer, contention quiets down. Like charcoal to hot embers and wood to fire, so is a contentious man to kindle strife. The words of a whisperer are like dainty morsels, and they go down into the innermost parts of the body."
Proverbs 26:20-22

"Your tongue devises destruction, like a sharp razor, O worker of deceit."
Psalm 52:2

"Keep your tongue from evil and your lips from speaking deceit."
Psalm 34:13