Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:49:12 –

O you who have believed, avoid much ˹negative˺ assumption. Indeed, some assumption is sin. And do not spy or backbite each other. Would one of you like to eat the flesh of his brother when dead? You would detest it. And fear Allah; indeed, Allah is Accepting of repentance and Merciful.  

O you who believe, shun much suspicion. Indeed some suspicions are sins, that is to say, it causes one to fall into sin. This ˹suspicion˺ may have many forms, such as thinking ill of the good folk from among the believers — and such ˹good folk˺ are many — in contrast to the immoral individuals among them in whose case there is no sin, so long as it ˹the suspicion˺ is in accordance with their outward behaviour. And do not spy (tajassasū: one of the two tā’ letters ˹of tatajassasū˺ has been omitted): do not pursue the imperfections and faults of Muslims by searching them out; nor backbite one another, do not speak of him by ˹mentioning˺ something which he is averse to ˹having mentioned of himself˺, even if it be true. Would any of you love to eat the flesh of his brother dead? (read maytan or mayyitan). That is to say, it would not be right for him ˹to do so˺. You would abhor it. Thus to backbite him in life would be like eating his flesh when he is dead. This latter ˹form of behaviour˺ has been suggested to you and you were averse to it, so be averse to the former too. And fear God, that is, His punishment for backbiting, by repenting of it; assuredly God is Relenting, accepting of the penitence of those who repent, Merciful, to them.
القرآن:٤٩:١٢ –

يَا أَيُّهَا الَّذِينَ آمَنُوا اجْتَنِبُوا كَثِيرًا مِنَ الظَّنِّ إِنَّ بَعْضَ الظَّنِّ إِثْمٌ ۖ وَلَا تَجَسَّسُوا وَلَا يَغْتَبْ بَعْضُكُمْ بَعْضًا ۚ أَيُحِبُّ أَحَدُكُمْ أَنْ يَأْكُلَ لَحْمَ أَخِيهِ مَيْتًا فَكَرِهْتُمُوهُ ۚ وَاتَّقُوا اللَّهَ ۚ إِنَّ اللَّهَ تَوَّابٌ رَحِيمٌ  

{يا أيها الذين آمنوا اجتنبوا كثيرا من الظن إن بعض الظن إثم} أي مؤثم وهو كثير كظن السوء بأهل الخير من المؤمنين، وهم كثير بخلافه بالفساق منهم فلا إثم فيه في نحو يظهر منهم {ولا تجسسوا} حذف منه إحدى التاءين لا تتبعوا عورات المسلمين ومعايبهم بالبحث عنها {ولا يغتب بعضكم بعضا} لا يذكره بشيء يكرهه وإن كان فيه {أيجب أحدكم أن يأكل لحم أخيه ميتا} بالتخفيف والتشديد، أي لا يحسن به {فكرهتموه} أي فاغتيابه في حياته كأكل لحمه بعد مماته وقد عرض عليكم الثاني فكرهتموه فاكرهوا الأول {واتقوا الله} أي عقابه في الاغتياب بأن تتوبوا منه {إن الله توَّاب} قابل توبة التائبين {رحيم} بهم.