Quran 20:56 · Taha

Moses continued to preach to Pharaoh over a long period of time, using rational arguments and also showing him miracles of a physical nature. But Pharaoh did not believe in Moses. In reality, admitting the truth of Moses’s preaching would have amounted to a negation of himself—something which his proud and egoistic mentality would never permit. Pharaoh tried to nullify Moses’s rational arguments by means of irrelevant pleas. On the subject of his miracles, Pharaoh alleged that they were simply magic, i.e., something which had no relevance to God, and insisted that anybody could acquire the necessary expertise to perform such feats. In order to keep up his boastful assertions, he said that he, through his magicians, could perform the same feats or miracles as Moses had demonstrated. After some discussion, it was finally decided that, at the forthcoming national fair, magicians of the country should gather, and there should be a competition between them and Moses before all the people.