Is it permissible to slaughter a goat kid instead of a ram for a vow due to financial hardship, and is it permissible for the one making the vow or any of his children to eat from the vow?

A vow must be fulfilled, and it is not permissible to substitute it with anything unless it is better. Jurists have stipulated that lamb is superior to goat, as its meat is more palatable. This is supported by the Prophet, peace and blessings be upon him, who said: "The best sacrifice is the horned ram," and by Umm Salamah, who said: "For me to sacrifice a young lamb is more beloved to me than to sacrifice an old goat." Therefore, if someone vows to slaughter a lamb, it is not permissible for him to switch to slaughtering a kid goat. He must wait until he is able to slaughter what he vowed.