Surah Fusilat (The Verses Prefectly Explained), Verse 13

فَاِنْ اَعْرَضُوْا فَقُلْ اَنْذَرْتُكُمْ صٰعِقَةً مِّثْلَ صٰعِقَةِ عَادٍ وَّثَمُوْدَ ۟

Fa-in a'radoo faqul anzartukum saa'iqatam misla saa'iqati 'Aadinw wa Samood

“But if they turn away, say thou: "I have warned you of a stunning Punishment (as of thunder and lightning) like that which (overtook) the 'Ad and the Thamud!"”

Quran 41:13 (Yusuf Ali Translation)