Thumma baAAathna min baAAdihim moosa bi-ayatina ila firAAawna wamala-ihi fathalamoo biha fanuthur (surah Araf: 103)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(7:103) After those We sent forth Moses with Our signs to Pharaoh and his nobles, *83 but they dealt with Our signs unjustly. *84 Observe, then, what happened to the mischief-makers.

Summa ba`asnaa mim ba`dihim Moosaa bi Aayaatinaaa ilaa Fir`awana wa mala`ihee fazalamoo bihaa fanzur kaifa kaana `aaqibatul mufsideen

*83). The stories narrated in the Qur'an bring home unmistakenly the point that people who reject God's Message are not spared; rather they are destroyed. In narrating at length the story of Moses, Pharaoh and the Israelites, the Qur'an provides some important lessons for the unbelieving Quraysh, the Jews, and also the believers.
The Quraysh are advised that the apparently large differences in the numerical strength of the forces of truth and falsehood in the early phase of the Islamic movement should not lead them to entertain any, kind of illusion. History, provides ample testimony that the Message of truth has always had a very humble beginning. That its proponent, initially, is in the hopelessly small minority of one; in fact, one in the whole world. He then proceeds, despite his resource lessness, to challenge the hegemony of falsehood, to declare war against it, despite the fact that falsehood is backed by powerful states and empires. And ultimately the truth triumphs. The Quraysh are also reminded that all conspiracies hatched against the Prophets and all the means employed to suppress the Message of truth are ultimately foiled. They are further told that God grants long terms of respite to the evil-doing nations so that they might mend their ways and reform themselves. But when they persistently disregard all warnings and learn no lesson from instructive events, He smites them with an exemplary punishment.
Some further lessons are meant to be conveyed to those who believed in the Prophet (peace be on him). First, that they should not feel disheartened by the paucity of resources, nor be overawed by the impressive numerical strength, pomp and grandeur of their enemies. Nor should they lose heart if they find that God's help does not come at the expected hour. Second, that those who follow in the footsteps of the Jews are bound, ultimately, to be seized by the same curse which afflicted the Jews.
As for the Israelites, they are warned against the evil effects of clinging to falsehood. Illustrations of this were provided by important events in their own history. They are also asked to purge the Message of the earlier Prophets of all accretions and distortions and to restore it to its original purity.
*84). 'They dealt with Our signs unjustly' refers to their rejection of God's signs and to the fact that they dismissed them as sheer sorcery. If a person scoffs at a beautiful couplet, and dubs it as amateurish rhyming, this amounts to committing an offence against poetry itself. Likewise, to brand those extraordinary acts of God as sorcery and magic - even though magicians declared that those acts were beyond their ability - constitutes a serious offence not only against God's signs but also against common sense and truth.