“Killing by mistake that resembles intentionally, is killing with a whip or stick, for which the blood money is one hundred camels, of which forty should be pregnant she-camels in middle of their pregnancies, with their young in their wombs.”

Another chain reports a similar hadith.
Sunan Ibn Majah Book 21, Hadith 13
← Previous Hadith “Whoever kills deliberately, he will be handed over to the heirs of the victim. If they want, they may kill him, or if they want, they may accept the blood money, which is thirty Hiqqah, thirty Jadha'ah and forty Khalifah. This is the blood money for deliberate slaying. Whatever is settled by reconciliation belongs to them, and that is a binding covenant.”

Sunan Ibn Majah Book 21, Hadith 12 Next Hadith → the Messenger of Allah (ﷺ) stood up on the Day of the conquest of Makkah, on the steps of the Ka'bah. He praised and glorified Allah (SWT), then he said: “Praise is to Allah (SWT) who has fulfilled His promise, granted victory to His slave and defeated the Confederates alone. The one who is killed by mistake is the one who is killed with a whip or a stick; for him the blood money is one hundred camels, of which forty should be pregnant she-camels with their youngs in their wombs. Every custom of Ignorance period, and every blood claim, is beneath these two feet of mine (i.e. is abolished), except for the custodianship of the Ka'bah and the provision of water for the pilgrims, which I confirm still belong to the people to whom they belonged before.”

Sunan Ibn Majah Book 21, Hadith 14