فَاِنۡ اَعۡرَضُوۡا فَقُلۡ اَنۡذَرۡتُكُمۡ صٰعِقَةً مِّثۡلَ صٰعِقَةِ عَادٍ وَّثَمُوۡدَؕ‏

But if they turn away, then say, "I have warned you of a thunderbolt like the thunderbolt [that struck] 'Aad and Thamud