That is because Allah would not change a favor which He had bestowed upon a people until they change what is within themselves. And indeed, Allah is Hearing and Knowing.

[Theirs is] like the custom of the people of Pharaoh and of those before them. They denied the signs of their Lord, so We destroyed them for their sins, and We drowned the people of Pharaoh. And all [of them] were wrongdoers.

Indeed, the worst of living creatures in the sight of Allah are those who have disbelieved, and they will not [ever] believe -

The ones with whom you made a treaty but then they break their pledge every time, and they do not fear Allah.

So if you, [O Muhammad], gain dominance over them in war, disperse by [means of] them those behind them that perhaps they will be reminded.