It is auspicious to dream of a coffin, especially when there are people lying inside. Officials will be promoted, businessmen will profit, and ordinary people will be lucky! If it is an empty coffin, success will not be as good as expected.
Mother is not at home, which means that mother and father are separated by yin and yang, so this dream is reasonable and your mother will be safe and healthy.
Another interesting thing is that you asked your father what to eat, and his father said that cooking soup corresponds to an empty coffin, which may indicate that your recent work has achieved little success, but it is not as good as expected. In addition, according to superstition, it is also possible that your father is short of money, so you should burn some paper money for him.