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
bukhari:3181 – ʿAbdān > Abū Ḥamzah > al-Aʿmash > Saʾalt Abū Wāʾil Shahidt Ṣiffīn > Naʿam > Sahl b. Ḥunayf > Āttahimūā Raʾyakum Raʾaytunī Yawm Abū Jandal And Law Astaṭīʿ

I asked Abu Wail, "Did you take part in the battle of Siffin?" He said, 'Yes, and I heard Sahl bin Hunaif (when he was blamed for lack of zeal for fighting) saying, "You'd better blame your wrong opinions. I wish you had seen me on the day of Abu Jandal. If I had the courage to disobey the Prophet's orders, I would have done so. We had kept out swords on our necks and shoulders, for a thing which frightened us. And we did so, we found it easier for us, except in the case of the above battle (of ours).' "  

البخاري:٣١٨١ – حَدَّثَنَا عَبْدَانُ أَخْبَرَنَا أَبُو حَمْزَةَ قَالَ سَمِعْتُ الأَعْمَشَ قَالَ سَأَلْتُ أَبَا وَائِلٍ شَهِدْتَ صِفِّينَ قَالَ نَعَمْ فَسَمِعْتُ سَهْلَ بْنَ حُنَيْفٍ يَقُولُ اتَّهِمُوا رَأْيَكُمْ رَأَيْتُنِي يَوْمَ أَبِي جَنْدَلٍ وَلَوْ أَسْتَطِيعُ

أَنْ أَرُدَّ أَمْرَ النَّبِيِّ ﷺ لَرَدَدْتُهُ وَمَا وَضَعْنَا أَسْيَافَنَا عَلَى عَوَاتِقِنَا لأَمْرٍ يُفْظِعُنَا إِلاَّ أَسْهَلْنَ بِنَا إِلَى أَمْرٍ نَعْرِفُهُ غَيْرِ أَمْرِنَا هَذَا  

See similar narrations below:

Collected by Muslim, Aḥmad, Ṭabarānī
muslim:1785b – Abū Kurayb Muḥammad b. al-ʿAlāʾ And Muḥammad b. ʿAbdullāh b. Numayr > Abū Muʿāwiyah > al-Aʿmash > Shaqīq > Sahl b. Ḥunayf

I heard Sahl b. Hunaif say at Siffin: O ye people, find fault with your (own) discretion. By Allah, on the Day of Abu Jandal (i. e. the day of Hudaibiya), I thought to myself that, if I could, I would reverse the order of the Messenger of Allah ﷺ (the terms of the truce being unpalatable). By Allah, we have never hung our swords on our shoulders in any situation whatsoever except when they made easy for us to realise the goal envisaged by us, but this battle of yours (seems to be an exception). Ibn Numair (in his version) did not mention the words:" In any situation whatsoever"  

مسلم:١٧٨٥b – وَحَدَّثَنَا أَبُو كُرَيْبٍ مُحَمَّدُ بْنُ الْعَلاَءِ وَمُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ قَالاَ حَدَّثَنَا أَبُو مُعَاوِيَةَ عَنِ الأَعْمَشِ عَنْ شَقِيقٍ قَالَ سَمِعْتُ سَهْلَ بْنَ حُنَيْفٍ يَقُولُ بِصِفِّينَ أَيُّهَا النَّاسُ اتَّهِمُوا رَأْيَكُمْ وَاللَّهِ لَقَدْ رَأَيْتُنِي يَوْمَ أَبِي جَنْدَلٍ وَلَوْ أَنِّي أَسْتَطِيعُ

أَنْ أَرُدَّ أَمْرَ رَسُولِ اللَّهِ ﷺ لَرَدَدْتُهُ وَاللَّهِ مَا وَضَعْنَا سُيُوفَنَا عَلَى عَوَاتِقِنَا إِلَى أَمْرٍ قَطُّ إِلاَّ أَسْهَلْنَ بِنَا إِلَى أَمْرٍ نَعْرِفُهُ إِلاَّ أَمْرَكُمْ هَذَا لَمْ يَذْكُرِ ابْنُ نُمَيْرٍ إِلَى أَمْرٍ قَطُّ  

ahmad:15974 – Sufyān b. ʿUyaynah > al-Aʿmash > Abū Wāʾil > Sahl b. Ḥunayf Āttahimūā Raʾyakum Falaqad Raʾaytunā Yawm Abū Jandal And Law Nastaṭīʿ > Narud Amrah Laradadnāh Wa-al-Lh Mā Waḍaʿnā Suyūfanā

[Machine] "To return his matter we will respond to him, I swear to God, we have never removed our swords from our shoulders since we surrendered to a command that intimidates us, except for what is easier for us to a matter that we know, and the only matter we have not defeated an opponent, except that another opponent opens to us."  

أحمد:١٥٩٧٤ – حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ قَالَ حَدَّثَنَا الْأَعْمَشُ عَنْ أَبِي وَائِلٍ قَالَ قَالَ سَهْلُ بْنُ حُنَيْفٍ اتَّهِمُوا رَأْيَكُمْ فَلَقَدْ رَأَيْتُنَا يَوْمَ أَبِي جَنْدَلٍ وَلَوْ نَسْتَطِيعُ

أَنْ نَرُدَّ أَمْرَهُ لَرَدَدْنَاهُ وَاللهِ مَا وَضَعْنَا سُيُوفَنَا عَنْ عَوَاتِقِنَا مُنْذُ أَسْلَمْنَا لِأَمْرٍ يُفْظِعُنَا إِلَّا أَسْهَلَ بِنَا إِلَى أَمْرٍ نَعْرِفُهُ إِلَّا هَذَا الْأَمْرَ مَا سَدَدْنَا خَصْمًا إِلَّا انْفَتَحَ لَنَا خَصْمٌ آخَرُ  

tabarani:5601 – ʿUbayd b. Ghannām > Abū Bakr b. Abū Shaybah > Abū Muʿāwiyah > al-Aʿmash > Shaqīq > Sahl b. Ḥunayf Biṣiffīn

I heard Sahl b. Hunaif say at Siffin: O ye people, find fault with your (own) discretion. By Allah, on the Day of Abu Jandal (i. e. the day of Hudaibiya), I thought to myself that, if I could, I would reverse the order of the Messenger of Allah ﷺ (the terms of the truce being unpalatable). By Allah, we have never hung our swords on our shoulders in any situation whatsoever except when they made easy for us to realise the goal envisaged by us, but this battle of yours (seems to be an exception). Ibn Numair (in his version) did not mention the words:" In any situation whatsoever" (Using translation from Muslim 1785b)   

الطبراني:٥٦٠١ – حَدَّثَنَا عُبَيْدُ بْنُ غَنَّامٍ ثنا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ثنا أَبُو مُعَاوِيَةَ عَنِ الْأَعْمَشِ عَنْ شَقِيقٍ قَالَ سَمِعْتُ سَهْلَ بْنَ حُنَيْفٍ بِصِفِّينَ يَقُولُ «يَا أَيُّهَا النَّاسُ §اتَّهِمُوا رَأْيَكُمْ وَاللهِ لَقَدْ رَأَيْتُنِي يَوْمَ أَبِي جَنْدَلٍ وَلَوْ أَسْتَطِيعُ

أَنْ أَرُدَّ أَمْرَ رَسُولِ اللهِ ﷺ لَرَدَدْتُهُ وَاللهِ مَا وَضَعْنَا سُيُوفَنَا عَلَى عَوَاتِقِنَا إِلَى أَمْرٍ قَطُّ إِلَّا أَسْهَلَ بِنَا إِلَى أَمْرٍ نَعْرِفُهُ إِلَّا أَمْرَكُمْ هَذَا»