فَإِنۡ أَعۡرَضُواْ فَقُلۡ أَنذَرۡتُكُمۡ صَٰعِقَةٗ مِّثۡلَ صَٰعِقَةِ عَادٖ وَثَمُودَ
Fa-in a'radoo faqul anzartukum saa'iqatam misla saa'iqati 'Aadinw wa Samood
English Translation
But if they turn away, then say, "I have warned you of a thunderbolt like the thunderbolt [that struck] 'Aad and Thamud
— Saheeh International