O ye who believe! Avoid much suspicion; for suspicion in some cases is a sin. And spy not, neither backbite one another. Would any of you like to eat the flesh of his brother who is dead? Certainly you would loathe it. And fear Allah, surely, Allah is Oft-Returning with compassion and is Merciful.
ISLAM, THE HOLY QUR’AN, 49:13
The believer is not a slanderer, nor does he curse others, and nor is he immoral or shameless.
ISLAM, THE HOLY PROPHET (SA), JAMI‘ ALTIRMIDHI
The ailment of ill-thinking is so wretched an affliction that it blinds a man and hurls him into the dark pit of ruin. It is ill-thinking which resulted in the worship of a dead man. Indeed, it is ill-thinking which moves people to strip God Almighty of His attributes of creation, mercy and granting provision, etc., reducing Him, God forbid, to an idle and useless being. Therefore, it is due to this very ill-thinking that a vast part of hell shall be occupied, rather it would not be an exaggeration to state that the entirety of it would be filled by such people.
ISLAM, THE PROMISED MESSIAH (AS), MALFUZAT – VOLUME I, P. 96
You shall not go around as a slanderer among your people, and you shall not profit by the blood of your neighbour.
JUDAISM, LEVITICUS 19:14
And the tongue is a fire. The tongue is placed among our members as a world of iniquity; it stains the whole body, sets on fire the cycle of nature, and is itself set on fire by hell. For every species of beast and bird, of reptile and sea creature, can be tamed and has been tamed by the human species, but no one can tame the tongue – a restless evil, full of deadly poison. With it we bless the Lord and Father, and with it we curse those who are made in the likeness of God.
CHRISTIANITY, THE BIBLE, JOHN 15:13
Speak not harshly to anyone. Those thus addressed will retort. Painful, indeed, is vindictive speech. Blows in exchange may bruise you.
BUDDHISM, DHAMMAPADA 133