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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
nasai-kubra:6885 – Muḥammad b. Rāfiʿ al-Naysābūrī > ʿAbd al-Razzāq > Maʿmar > al-Zuhrī > Ibn al-Musayyib

"Qasamah existed during the Jahiliyyah, then the Messenger of Allah confirmed it in the case of an Ansari who was found slain in the dry well of the jews, and Ansar said: "The Jews kill our companion."' (Using translation from Nasāʾī 4709)  

الكبرى للنسائي:٦٨٨٥ – أَخْبَرَنَا مُحَمَّدُ بْنُ رَافِعٍ النَّيْسَابُورِيُّ قَالَ حَدَّثَنَا عَبْدُ الرَّزَّاقِ قَالَ أَخْبَرَنَا مَعْمَرٌ عَنِ الزُّهْرِيِّ عَنِ ابْنِ الْمُسَيِّبِ قَالَ

كَانَتِ الْقَسَامَةُ فِي الْجَاهِلِيَّةِ ثُمَّ أَقَرَّهَا رَسُولُ اللهِ ﷺ فِي الْأَنْصَارِيِّ الَّذِي وُجِدَ مَقْتُولًا فِي جُبِّ الْيَهُودِ فَقَالَتِ الْأَنْصَارُ «إِنَّ الْيَهُودَ قَتَلُوا صَاحِبَنَا»  

See similar narrations below:

Collected by Nasāʾī
nasai:4709 – Muḥammad b. Rāfiʿ > ʿAbd al-Razzāq > Maʿmar > al-Zuhrī > Ibn al-Musayyab

"Qasamah existed during the Jahiliyyah, then the Messenger of Allah confirmed it in the case of an Ansari who was found slain in the dry well of the jews, and Ansar said: "The Jews kill our companion."'  

النسائي:٤٧٠٩ – أَخْبَرَنَا مُحَمَّدُ بْنُ رَافِعٍ قَالَ حَدَّثَنَا عَبْدُ الرَّزَّاقِ قَالَ أَنْبَأَنَا مَعْمَرٌ عَنِ الزُّهْرِيِّ عَنِ ابْنِ الْمُسَيَّبِ قَالَ

كَانَتِ الْقَسَامَةُ فِي الْجَاهِلِيَّةِ ثُمَّ أَقَرَّهَا رَسُولُ اللَّهِ ﷺ فِي الأَنْصَارِيِّ الَّذِي وُجِدَ مَقْتُولاً فِي جُبِّ الْيَهُودِ فَقَالَتِ الأَنْصَارُ الْيَهُودُ قَتَلُوا صَاحِبَنَا