Fussilat 41:13

Fa-in aAAradoo fuqul anthartukumsaAAiqatan mithla saAAiqati AAadin wathamood

But if they turn away, then say, "I have warned you of a thunderbolt like the thunderbolt [that struck] ʿAad and Thamūd.

So, if they turn away, then say, “I have warned you of a calamity like the calamity of ‘Ād and Thamūd,