What is the ruling concerning my vow made in high school to sacrifice a sheep, and should I divide it and send it out, or give it to the poor, or sacrifice more than one sheep, and is it permissible to slaughter it at a joyous occasion with the intention of fulfilling the vow?

The gist of the fatwa: A Muslim is not obligated by anything if he vows something he does not own. The basic principle is to fulfill vows, based on the Almighty's saying: "And let them fulfill their vows," and the Prophet's (peace be upon him) saying: "Whoever vows to obey Allah, let him obey Him." If the intention was to make the vow contingent upon giving the father something, and that did not happen, then nothing is obligatory. And if the intention was to fulfill the vow from the father's money, which the one making the vow does not own, then this is not valid and nothing is obligatory from it, based on the Prophet's (peace be upon him) saying: "There is no vow upon the son of Adam concerning what he does not own."