Vowing to slaughter a mature camel for each child he has

Q: A man is married to more than one wife, but none of them gave birth to any children. The man was anxious to have children, so he vowed that he would slaughter an aged camel for each child that Allah may grant him. Allah blessed him with fifteen children, nine boys and six girls. To keep his vow, the man slaughtered five aged camels, but he was unable to slaughter the rest. The man died, but before his death, he told his children that he had vowed to slaughter the camels for every boy, not girl that he was granted. He left behind a small amount of money and now his sons want to keep his vow. Your Eminence, we would like to know your advice in this matter. Is it permissible to slaughter young camels, which are more available in the market nowadays, due to the lack of aged camels? If it is permissible for us to slaughter young camels, how should they be slaughtered and distributed? It should be noted that the man, who made this vow, is now dead and his heirs mention that he only left behind a modest house. He also did not make a will in one-third of his wealth to be given as charity, because he died suddenly and his last words were not clear. His house was sold for 60,000 but the heirs have not yet been given their shares of the estate. The questioner mentions that aged camels are not sold for slaughter now, but are sold for their milk instead and are very expensive. (Part No. 23; Page No. 270) The seven boys and five girls as well as the two widows he left would like Your Eminence to reply to them in writing. May Allah protect you.

A: Firstly: If the reality is as you have mentioned, that your father vowed to slaughter some camels and could not slaughter them all, then his children should slaughter the remaining aged camels that he vowed to slaughter from the money resulting from selling the house. But if that is not enough, then the sons, being eager to keep their father's vow, should slaughter as many as they can of the other aged camels, because Allah (Exalted be He) says, So keep your duty to Allâh and fear Him as much as you can Secondly: If your father died without making a will for one-third of his wealth to be given in charity, you do not have to give one-third of his wealth to charity. It is recommended that you stay dutiful to your father after his death, by giving charity on his behalf and supplicating to Allah to have mercy on him and to forgive him.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.