Musnad Ahmad 4274

It was narrated that Ibn Mas'ood said: The Messenger of Allah (ﷺ) ruled that the diyah in the case of accidental killing should be twenty she-camels in their second year, twenty he-cameIs in their second year, twenty she-camels in their third year, twenty she-camels in their fourth year, and twenty she-camels in their fifth year.