Sunan an-Nasa'i, Volume 5, Book 45, Hadith 4799 (DarusSalam)

It was narrated from 'Uqbah bin 'Aws, that the Mssenger of Allah said: "Indeed the accidental killing, the killing with a whip or stick, for it (the Diyah) is one hundred camels - a severe penalty - of which forty should be (she-camels) with their young in their wombs."

أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ، عَنِ ابْنِ أَبِي عَدِيٍّ، عَنْ خَالِدٍ، عَنِ الْقَاسِمِ، عَنْ عُقْبَةَ بْنِ أَوْسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ أَلاَ إِنَّ قَتِيلَ الْخَطَإِ قَتِيلَ السَّوْطِ وَالْعَصَا فِيهِ مِائَةٌ مِنَ الإِبِلِ مُغَلَّظَةٌ أَرْبَعُونَ مِنْهَا فِي بُطُونِهَا أَوْلاَدُهَا ‏" ‏ ‏.‏

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