The Quran

وَلَو نَشاءُ لَمَسَخناهُم عَلىٰ مَكانَتِهِم فَمَا استَطاعوا مُضِيًّا وَلا يَرجِعونَ

Muhammad Asad

And had it been Our will [that they should not be free to choose between right and wrong], We could surely have given them a different nature¹ [and created them as beings rooted] in their places, so that they would not be able to move forward, and could not turn back.²

Lit., "transformed [or "transmuted"] them".
I.e., if it had been God's will that men should have no freedom of will or moral choice, He would have endowed them from the very beginning with a spiritually and morally stationary nature, entirely rooted in their instincts ("in their places"), devoid of all urge to advance, and incapable either of positive development or of retreat from a wrong course.