But if they turn away, then say, "I have warned you of a thunderbolt like the thunderbolt [that struck] 'Aad and Thamud.
The Saheeh International Quran Translation
فَإِنْ أَعْرَضُوا۟ فَقُلْ أَنذَرْتُكُمْ صَٰعِقَةً مِّثْلَ صَٰعِقَةِ عَادٍ وَثَمُودَBut if they turn away, then say, "I have warned you of a thunderbolt like the thunderbolt [that struck] 'Aad and Thamud.