The Prophet (ﷺ) said: He who is two-faced in this world will have two tongues of fire on the Day of Resurrection.
Sunan Abi Dawud Book 43, Hadith 101
← Previous Hadith The worst of the people is a man who is double-faced; he presents one face to some and another to others.

Sunan Abi Dawud Book 43, Hadith 100 Next Hadith → The Messenger of Allah (ﷺ) was asked: Messenger of Allah! What is back-biting? He replied: It is saying something about your brother which he would dislike. He was asked again: Tell me how the matter stands if what I say about my brother is true? He replied: If what you say of him is true, you have slandered him, and if what you say of him is not true, you have reviled him.

Sunan Abi Dawud Book 43, Hadith 102