Sunan an-Nasa'i 4709
سنن النسائي#4709Sahihأَخْبَرَنَا مُحَمَّدُ بْنُ رَافِعٍ، قَالَ حَدَّثَنَا عَبْدُ الرَّزَّاقِ، قَالَ أَنْبَأَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنِ ابْنِ الْمُسَيَّبِ، قَالَ كَانَتِ الْقَسَامَةُ فِي الْجَاهِلِيَّةِ ثُمَّ أَقَرَّهَا رَسُولُ اللَّهِ صلى الله عليه وسلم فِي الأَنْصَارِيِّ الَّذِي وُجِدَ مَقْتُولاً فِي جُبِّ الْيَهُودِ فَقَالَتِ الأَنْصَارُ الْيَهُودُ قَتَلُوا صَاحِبَنَا .
It was narrated that Ibn Al-Musayyab said:"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
Scholarly Authentication
The label above is the grade most of these scholars gave, each scholar counted once — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. When they judged only its chain of narrators (“Isnaad”), the label says “Sound chain”. Each scholar's own wording:
Our source also lists this ruling under Abu Ghuddah, the editor of the printed edition it was taken from. It is al-Albani's ruling printed again, so it is counted once.
In-book reference: 45:4