It was narrated from Ya'qub bin Aws that:

a man from among the Companions of the Prophet told him, that when the Messenger of Allah came to Makkah, in the Year of the Conquest, he said: "Indeed, accidental killing on purpose, is killing with a whip or stick, for which forty (she-camels) with their young in their wombs."

أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ بَزِيعٍ، قَالَ حَدَّثَنَا يَزِيدُ، قَالَ حَدَّثَنَا خَالِدٌ، عَنِ الْقَاسِمِ بْنِ رَبِيعَةَ، عَنْ يَعْقُوبَ بْنِ أَوْسٍ، أَنَّ رَجُلاً، مِنْ أَصْحَابِ النَّبِيِّ ﷺ حَدَّثَهُ أَنَّ رَسُولَ اللَّهِ ﷺ لَمَّا قَدِمَ مَكَّةَ عَامَ الْفَتْحِ قَالَ " أَلاَ وَإِنَّ قَتِيلَ الْخَطَإِ الْعَمْدِ قَتِيلَ السَّوْطِ وَالْعَصَا مِنْهَا أَرْبَعُونَ فِي بُطُونِهَا أَوْلاَدُهَا " .