To dream of a coffin symbolizes time spent in utero. If the coffin is empty, then it indicates issues that are proving difficult to resolve.
To see a body in a coffin implies that you will soon face hardship and a brief time of despair. Perhaps you will feel as if you have lost your individuality and liberty, or are not being permitted to express yourself. It's possible that some aspect of your life is coming to an end. You may need to sever the ties in a friendship or association.