What is the ruling on someone who took money to donate to a sick person but did not deliver it until the patient died, then vowed to give his first salary in charity upon moving to a higher position, knowing that he currently possesses the money and is able to give the charity, but he does not know what to do about his vow?

This person must repent and return the money they obtained to the entity from which they took it. If that is not possible, then the money must be given to another needy patient. They must also fulfill their vow, for the Prophet, peace and blessings be upon him, said: "Whoever vows to obey Allah, let him obey Him." If it is not possible to both return the money and fulfill the vow, then giving the money to the patient takes precedence over fulfilling the vow, because the rights of individuals take precedence over Allah's financial rights when there is a conflict.