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
ahmad:7337 – Sufyān > Abū al-Zinād > al-Aʿraj > Abū Hurayrah

[Machine] I heard Sufyan saying, "Beware of assumptions, for they are the most false of speech."  

أحمد:٧٣٣٧ – قرئَ عَلَى سُفْيَانَ سَمِعْتُ أَبَا الزِّنَادِ عَنِ الْأَعْرَجِ عَنْ أَبِي هُرَيْرَةَ

عَنِ النَّبِيِّ ﷺ فَسَمِعْتُ سُفْيَانَ يَقُولُ إِيَّاكُمْ وَالظَّنَّ فَإِنَّهُ أَكْذَبُ الْحَدِيثِ  

See similar narrations below:

Collected by Tirmidhī, Aḥmad
tirmidhi:1988 – Ibn Abū ʿUmar > Sufyān > Abū al-Zinād > al-Aʿraj > Abū Hurayrah

"Beware of Zann (suspicion), for indeed Zann is the falsest of speech."  

الترمذي:١٩٨٨ – حَدَّثَنَا ابْنُ أَبِي عُمَرَ حَدَّثَنَا سُفْيَانُ عَنْ أَبِي الزِّنَادِ عَنِ الأَعْرَجِ عَنْ أَبِي هُرَيْرَةَ

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِيَّاكُمْ وَالظَّنَّ فَإِنَّ الظَّنَّ أَكْذَبُ الْحَدِيثِ  

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ قَالَ وَسَمِعْتُ عَبْدَ بْنَ حُمَيْدٍ يَذْكُرُ عَنْ بَعْضِ أَصْحَابِ سُفْيَانَ قَالَ قَالَ سُفْيَانُ الظَّنُّ ظَنَّانِ فَظَنٌّ إِثْمٌ وَظَنٌّ لَيْسَ بِإِثْمٍ فَأَمَّا الظَّنُّ الَّذِي هُوَ إِثْمٌ فَالَّذِي يَظُنُّ ظَنًّا وَيَتَكَلَّمُ بِهِ وَأَمَّا الظَّنُّ الَّذِي لَيْسَ بِإِثْمٍ فَالَّذِي يَظُنُّ وَلاَ يَتَكَلَّمُ بِهِ
ahmad:10553 – Yazīd > Salīm b. Ḥayyān > Abū > Abū Hurayrah

Messenger of Allah ﷺ said, 'Beware of suspicion, for it is the worst of false tales and don't look for the other's faults and don't spy and don't hate each other, and don't desert (cut your relations with) one another O Allah's slaves, be brothers!" (See Hadith No. 90) (Using translation from Bukhārī 6724)  

أحمد:١٠٥٥٣ – حَدَّثَنَا يَزِيدُ أَخْبَرَنَا سَلِيمُ بْنُ حَيَّانَ قَالَ سَمِعْتُ أَبِي يُحَدِّثُ قَالَ سَمِعْتُ أَبَا هُرَيْرَةَ قَالَ

قَالَ رَسُولُ اللهِ ﷺ إِيَّاكُمْ وَالظَّنَّ فَإِنَّ الظَّنَّ أَكْذَبُ الْحَدِيثِ