As for those who differentiate between a vow and obligatory fasting, the vow was obligatory for him by God, and the obligatory fasting, which is Ramadan, was obligatory for him, starting from the obligation of the servant, so when the servant had the duty of the vow to act according to his obligation, his guardian fasted on his behalf, because it is about the obligation of a servant, so a servant like him will act on his behalf in that. Until he cleared his duty, and the obligatory fasting from the beginning was not for the servant to do, so what was obligatory for him was the one who killed him, so if he left it, he would fast, so the blood money would be borne by the killer. And God Almighty said about whoever goes out as an emigrator to God.