Vowing to slaughter an animal if his son gets better

Q 6: A person vowed to slaughter a sacrificial animal for the Sake of Allah, if his son returned safely from a certain dangerous place. Praise be to Allah, the son returned safely. There is a poor family and orphans that live near them, is it permissible to give those orphans the value of the sacrifice in cash in Saudi Riyals, or any other currency?

A: You should slaughter the sacrificial animal in order to fulfill your vow, carry out your intention and thank Allah for the safe return of your son. The sacrificial animal should (Part No. 23; Page No. 394) at least be of average value, of the type you intended or according the `Urf (custom) in similar cases. It is not permissible to pay its value to the poor, or to orphans as long as it is possible to fulfill the original vow.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.