Surah 39. Az-Zumar, Ayah 27

As in many other passages of the Qur'an, the use of the term "parable" (mathal) immediately or shortly after a description of men's condition - whether good or bad - in the hereafter is meant to remind us that all such descriptions relate to something that is "beyond the reach of a created being's perception" (al-ghayb), and cannot, therefore, be conveyed to man otherwise than by means of allegories or parables expressed in terms of human experience and therefore accessible, in a general sense, to human imagination.

Men can only understand high spiritual truths by parables and similitudes and these are given abundantly in the Qur-an. The object is, not merely to tell stories, but to teach lessons of spiritual wisdom.