Abu Dawud Book 34, Hadith Number 4536.
Chapter : Bloodwit for accidental killing that is quasiintentional killing.
Narated By ‘Ali : The bloodwit for unintentional murder is in four parts: twenty-five she-camels in their fourth year, twenty-five she-camels in their fifth year, twenty-five she-camels in their third year, and twenty-five she-camels in their second year.