Hadith 1732 - Bab 326 (Prohibition of Calling a Muslim an Infidel)
Chapter 18 (The Book of the Prohibited actions)

Ibn 'Umar (May Allah be pleased with them) said: The Messenger of Allah (Peace be upon him) said, "When a person calls his brother (in Islam) a disbeliever, one of them will certainly deserve the title. If the addressee is so as he has asserted, the disbelief of the man is confirmed, but if it is untrue, then it will revert to him."

[Al-Bukhari and Muslim].

Selon Ibn "Omar (das), le Messager de Dieu (bsdl) a dit: «Quand l"homme dit à son frère: «Espèce de mécréant!» l"un des deux a sûrement mérité ce titre. Il s"applique à l"autre si ce qu"il a dit est vrai, sinon c"est à lui qu"il revient».

Hadith 1733 - Bab 326 (Prohibition of Calling a Muslim an Infidel)
Chapter 18 (The Book of the Prohibited actions)

Abu Dharr (May Allah be pleased with him) said: I heard the Messenger of Allah (Peace be upon him) saying, "If somebody accuses another of disbelief or calls him the enemy of Allah, such an accusation will revert to him (the accuser) if the accused is innocent."

[Al-Bukhari and Muslim].

Abou Dharr (das) rapporte qu"il a entendu le Messager de Dieu (bsdl) dire: «Celui qui traite un autre de mécréant ou d"ennemi de Dieu alors qu"il ne l"est pas, c"est contre lui que retourne sa propre accusation».