وَالْبَلَدُ الطَّيِّبُ يَخْرُجُ نَبَاتُهُ بِإِذْنِ رَبِّهِ ۖ وَالَّذِي خَبُثَ لَا يَخْرُجُ إِلَّا نَكِدًا ۚ كَذَٰلِكَ نُصَرِّفُ الْآيَاتِ لِقَوْمٍ يَشْكُرُونَ (58)
(7:58) As for the good land, vegetation comes forth in abundance by the command of its Lord, whereas from the bad land, only poor vegetation comes forth. *46 Thus do We expound Our signs in diverse ways for a people who are grateful.
*46). It is necessary to grasp the subtle point made here in order to appreciate the full purport of what is being said. The reference to rain and its advantages is intended to bring into focus God's power, and to affirm life after death. Moreover, it is also intended to draw attention in allegorical, albeit graphic, terms to the blessings of prophethood, and how it helps men to distinguish between good and evil, between pure and impure. The intimation of Divine Guidance through the Prophets is compared to the movement of winds, the appearance of rain-laden clouds, and the fall of life-sustaining raindrops. In the same way as rainfall causes dead earth to be revived and makes the hidden treasures of life burst forth from its womb, so the impact of the teachings of the Prophets also brings dead humanity back to life, causing the hidden goodness in men to burst forth.
This allegory also hints at another important fact. In the same way that only fertile soil profits from rainfall, so only men of a righteous nature can profit from the blessings of prophethood. As for the wicked, they are like wasteland. Rainfall can cause such a land to bring forth only thorny bushes and cacti. Similarly, when the wicked come into contact with the teaching of the Prophets, the hidden evils of their nature come into full play.
This allegory is followed by a well-sustained account with illustrations from history showing that whenever the Prophets preach their Message, men Split into two camps. The righteous receive the blessings of prophethood and flourish, bringing forth the fruit of their goodness. As for the wicked, once the criterion provided by the Prophets is applied their impurities are fully exposed. This enables human society to purge itself of impurities in the same way as the goldsmith purges precious metals of alloy.