(Except for him who turns away and disbelieves), meaning: leave him to God. This was before he was commanded to fight them.
﴿إِلَّا من تولى وَكفر﴾ أَيْ: فَكِلْهُ إِلَى اللَّهِ، وَكَانَ هَذَا قبل أَن يُؤمر بقتالهم