“We created them and strengthened their forms [asrahum],” meaning: their creation.

Muhammad said: The root of the word comes from "al-isar," which is the binding. It is said: "How excellent is the way he bound his saddle [qatahu]," meaning: how excellent is the way he strengthened it!

“And if We willed, We could replace them with others similar to them [amthalahum],” meaning: We would destroy them with punishment and replace them with others similar to them, or better than them.