They had uttered that first speech only so that they might reflect, consult together, and muster every resource of plot, guile, deceit, sorcery, and slander they possessed. Yet—far from it! By Allah, conjecture proved false and opinion went astray. How could falsehood, magic, and delirium ever stand against the extraordinary signs that the All-Judging caused to break the norms at the hands of His servant—the Interlocutor—His noble Messenger, whom He supported with proofs that dazzle the eyes and confound minds and intellects?

Concerning their words,
“So agree on your strategy,” meaning: bring together everything you have,
“then come forward in ranks,” that is, as a single body.
They then urged one another to advance, for Pharaoh had promised and enticed them—“and Satan promises them nothing but delusion” (al-Nisāʾ 4:120).

“They said, ‘Moses, either you cast first, or we shall be the first to cast.’
He said, ‘No; you cast.’
Then suddenly their ropes and staffs seemed to him, by their magic, to be moving.
Moses felt a secret fear within himself.
We said, ‘Do not fear; you will indeed have the upper hand.
Cast what is in your right hand; it will swallow up what they have produced. They have produced only a magician’s trick, and the magician never prospers wherever he may be.’” (Tā Hā 20:65–69).

When the magicians had lined up and Moses and Aaron, peace be upon them, stood facing them, they said, “Either you cast before us, or we will cast before you.” He answered, “No; you cast.” They had prepared ropes and staffs and filled them with mercury and other devices that made those ropes and staffs writhe, so that to the onlooker they appeared to move of their own accord—though their motion came only from those contrivances. Thereupon they bewitched people’s eyes and struck them with awe, hurling down their ropes and staffs while chanting, “By the might of Pharaoh, we shall surely be the victors!”

Allah the Exalted says, “He said, ‘Cast.’ And when they cast, they bewitched the people’s eyes, intimidated them, and produced tremendous magic” (al-Aʿrāf 7:116).

He also says, “Suddenly their ropes and staffs seemed to him, by their magic, to be moving; and Moses felt a secret fear within himself” (Tā Hā 20:66-67)—meaning that he feared the people might be tempted by their sorcery and deceit before he was commanded to throw down what was in his hand, for he would do nothing without a command. Revelation then came to him at that very moment: “We said, ‘Do not fear; you will indeed be the uppermost. Cast what is in your right hand; it will swallow up what they have contrived. They have contrived only a magician’s trick, and the magician never prospers wherever he goes.’”

So Moses threw down his staff and declared, “What you have brought is sorcery; Allah will surely render it null and void. Truly, Allah does not set right the work of the corrupters. Allah establishes the truth by His words, even though the criminals detest it” (Yūnus 10:82).

Allah also says, “So Moses threw his staff, and behold, it swallowed up what they were falsifying” (al-Shuʿarāʾ 26:45). “Thus the truth was manifested, and what they had been doing was nullified; they were overcome then and there and turned back humbled. And the magicians fell down in prostration. They said, ‘We believe in the Lord of all worlds, the Lord of Moses and Aaron’” (al-Aʿrāf 7:118-122).

This happened because, when Moses—peace be upon him—threw it, it became an enormous serpent with legs, according to what others have reported.