Everything happens by the permission or Will of Allah.
Allah created the Satan, Satan disobeyed Allah. Allah knew that satan would do this. If Allah would have willed , Satan would not have disobeyed Allah,even if(satan) wanted to. So was this in Allah’s plan to let it happen so
What is this divine-destiny of Allah which people say limited free-will. Allah knows given the limited free-will, what man will do given the situation or a Test he is put to by Allah. Allahs knows the results before hand. He knows past ,present,future and He is in total control.
Only If I study hard for a schoolexam only then will I pass. Allah knows what grades I will get in my exam. So is it destiny that I will study hard for my school exam and pass. And also I made it happen due to my hard work as we-live-in cause-and-effect-world
Wa `alaykum salam,
Please read this post on the subject of Divine Will.