Tafsir of Ash-Shu`ara' 26:44

( "Cast down what you are going to cast." )

Peace be upon him did not truly intend to command [them to perform] magic and deception, for magic is forbidden and may even be disbelief; thus, it is not befitting for the infallible to command it. Rather, it was a permission to present what he knew—through inspiration, true insight, or situational indicators—that they would inevitably perform. Hence, he said: "what you are going to cast," in order to reach the point of invalidating it. This is like commanding a heretic to present his argument so that it may be refuted; there is no forbidden approval in this, for approval by way of critical appraisal is not the same as absolute approval, and the latter is not forbidden. The famous saying that "approval of disbelief is disbelief" is not absolute, as held by the scholars of jurisprudence and principles (Usul).

( "So they cast down their ropes and their staffs and said" )—that is, they said upon casting them—( "By the might of Pharaoh" )—meaning, by his power through which he prevents himself from oppression, derived from their saying "hard ground" (ard ‘azaz), meaning solid—( "Indeed, we are the victors" ).

It is apparent that this was an oath by them upon his might—may the curse be upon him—regarding [their] victory. They specified this particular oath here because of its suitability to victory. They swore to that because of their excessive self-assurance and their delivery of the utmost that could be produced of magic, and therein was an intimidation of Moses, peace be upon him, by their estimation. They shifted from direct address to the third person in their saying "By the might of Pharaoh" to glorify him. This oath is of the type of the oaths of the Age of Ignorance (Jahiliyyah).

Many Muslims today follow paths in swearing that are more heinous than their oaths; they are not content with swearing by Allah the Exalted and His attributes—Mighty and Majestic is He—nor do they consider that to be binding. Instead, one of them will swear by the bounty of the Sultan, or by his head, or by the head of the person being sworn to, or by his beard, or by the soil of his father's grave—only then do they consider the statement verified. They have other things they exalt and swear by, and it is not unlikely that swearing by Allah the Exalted falsely is less sinful than swearing by these things truthfully. This is a plague that has become widespread, and there is no power and no strength except in Allah, the Most High, the Almighty.

Ibn Atiyyah said, after mentioning that it was an oath: "It is more appropriate that it be by way of glorification and seeking blessings through his name, if they were worshipping him, just as you say when you begin something: 'In the name of Allah' or 'Upon the blessing of the Messenger of Allah, may Allah bless him and grant him peace,' and the like."