Ibn al-Sikkit al-Ahwazi asked Imam Rida (the eighth Shi'a Imam) some questions concerning essential differences of miracles of prophets. Imam's perspective concerning variable conditions of time and proportionality of miracle to such conditions is investigated in this essay. According to varia hie conditions of time, the miracle of Moses was refutation of sorcery, that of Jesus was healing the diseased as well as reviving the dead, and that of the holy prophet of Islam was the Quran. Quran is an eternal miracle which can always satisfy needs of men's developed minds
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