أَخْبَرَنِي يَحْيَى بْنُ حَبِيبِ بْنِ عَرَبِيٍّ، قَالَ أَنْبَأَنَا حَمَّادٌ، عَنْ خَالِدٍ، - يَعْنِي الْحَذَّاءَ - عَنِ الْقَاسِمِ بْنِ رَبِيعَةَ، عَنْ عُقْبَةَ بْنِ أَوْسٍ، عَنْ عَبْدِ اللَّهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ أَلاَ وَإِنَّ قَتِيلَ الْخَطَإِ شِبْهِ الْعَمْدِ مَا كَانَ بِالسَّوْطِ وَالْعَصَا مِائَةٌ مِنَ الإِبِلِ أَرْبَعُونَ فِي بُطُونِهَا أَوْلاَدُهَا ‏"‏ ‏.‏

It was narrated from Abdullah bin 'Amr that the prophet said: "Indeed the accidental killing, which seems intentional, with a whip or a stick, (the Diyah) is one hundred camels, of which forty should be (she-camels) with their young in their wombs." Translation Not Available

Book Ref: Sunan An Nisai Book 45 Hadith 4793
Web Ref:  Sunan An Nisai Vol 5 Book 45 Hadith 4797