Is it permissible to fulfill a vow to slaughter a sheep and distribute it to the poor, or to host a feast, in the event of the death of a disbeliever, knowing that the vow was made with "By Allah the Almighty"?

If the swearer intended the death of a specific person, then if that occurs, he must fulfill his oath by slaughtering a sheep and distributing it to the poor, or by inviting a group [to eat]. If he does not do so, he has broken his oath, and an expiation for the oath becomes obligatory upon him: feeding ten poor people, or clothing them, or freeing a slave. If he is unable to do that, then fasting for three days, based on the verse: "Allah will not impose blame upon you for what is unintentional in your oaths, but He will impose blame upon you for what you intended in your oaths. So its expiation is the feeding of ten poor people from the average of that which you feed your [own] families, or clothing them, or the freeing of a slave. But whoever cannot find [or afford it] - then a fast of three days. That is the expiation for oaths when you have sworn. And guard your oaths. Thus does Allah make clear to you His verses that you may be grateful." (Al-Ma'idah: 89).