Sacrificial fire and its attendant pain has many spiritual connotations. A funeral pyre suggests burning up or consuming that which is no longer spiritually necessary to us. A burning bush signifies divine knowledge imparted with passion.
The phoenix was believed to live for 500 or 600 years, then to burn itself on a funeral pyre, knowing it would rise again. In dreams, therefore, it can symbolize knowing when to move on, when to let the past go, being aware that there is more energy available if we do so.