Surah Fussilat 41:13

فَإِنْ أَعْرَضُوا۟ فَقُلْ أَنذَرْتُكُمْ صَـٰعِقَةً مِّثْلَ صَـٰعِقَةِ عَادٍ وَثَمُودَ

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

Translation: Saheeh International

Tafsir

But if they that is the Meccan disbelievers turn away from belief after this clear statement then say ‘I warn you of I threaten you with a thunderbolt like the thunderbolt of ‘Ād and Thamūd’ in other words a chastisement that will destroy you like the one that destroyed them.

Excerpt from Tafsir al-Jalalayn, commentary on 41:13, via Quran.com. The reader has the full commentary and 9 more tafsirs.