﴿ فَأَوْجَسَ فِى نَفْسِهِۦ خِيفَةًۭ مُّوسَىٰ ﴾

“and in his heart Moses became apprehensive.”

And Moses sensed fear within himself that is to say he feared that if the effect of their sorcery was of the same kind as his miracle he would become suspect in people’s minds and they would not believe in him.