Sunan an Nasai
4791
Sahih+2

It was narrated from Al-Qasim bin Rabi'ah, from 'Abdullah bin 'Amr, the Prophet said:"The accidental killing, which seems intentional, with a whip or stick, (the Diyah) is one hundred camels, of which forty should be (she-camels) which their young in their wombs

SahihAbu Ghuddah
SahihAl-Albani