Here the reference goes back to the past nations who did the same that was done to our prophet Mohammad (AS). As an instance Moses went to Pharaoh with nine clear signs, but eventually Pharaoh said to Moses:ِ
``O, Moses! I think of you to have been fascinated!''
Pharaoh and his chief accused Moses to have been well versed in sorcery and magic. They also called him to be mad! But Moses tried to convince them that he was brought up in Pharaoh's court in all the learning of the Egyptians. How then could he be mad, and when did he learn Egyptian magic inspite of being under the strict observance of Pharaoh's courtiers. On the other hand, what he showed as his nine miracles was far beyond the realm of magic and magician. What has magic to do with divine miracles!?
He therefore warned Pharaoh not to resist faith in God, or he would be doomed to perdition.