A Selection from my Favorite Jewish Sources
Rabbi Mordechai Levin
Tanakh, Leviticus 19:16
Do not go about as a talebearer among your countrymen… I am the Lord.”
Mishneh Torah, Hilchot Deiot, chapter 7:2
Who counts as a slanderer? One who carries matters from one [person] to another and says that so-and-so did such-and-such, or that he heard such-and-such regarding so-and-so is counted as a slanderer.
Mishneh Torah, Hilchot Deiot, chapter 7:3
The Sages said that there are three sins which `collect’ of a man in this world and deprive him of a share in the World To Come. These sins are idolatry, adultery and murder, but tale-bearing is above all. The Sages further said that tale-bearing is like denying God. The Sages further said that three types of tale-bearing kill – telling, listening and slandering. The sin of listening is worse than that of telling.
Mishneh Torah, Hilchot Deiot, chapter 7:6
It is forbidden to live in a neighborhood of tale-bearers, and how much more so sit with them and listen to what they say.
Talmud, Arakhin 15b
Slander is worse than the three cardinal sins of murder, forbidden sexual relationships and idol worship
Whoever tells lashon hara(slander or malicious gossip, whether true or false), God says of him: ‘He and I cannot inhabit the same world’
Pirkei DeRabi Eliezer 53
Whoever slanders has no place in the world to come
Talmud, Arachin 15b
The talk about third [persons] kills three persons: him who tells [the slander], him who accepts it, and him about whom it is told.
Talmud, Kidushin 70a
All who delegitimatize another person, and who refrain from seeing favorable merits in the other, delegitimatize in the other person the trait which is actually his own blemish
Tanakh, Proverbs 18:21
Death and life are in the hand of the tongue
Talmud, Arachin 15b
What is the meaning of: Death and life are in the hand [power] of the tongue? (Proverbs 18:21) Has the tongue ‘a hand’? It tells you that just as the hand can kill, so can the tongue.