فصّلت — Fussilat Ayat 13

فَاِنْ اَعْرَضُوْا فَقُلْ اَنْذَرْتُكُمْ صٰعِقَةً مِّثْلَ صٰعِقَةِ عَادٍ وَّثَمُوْدَ ۗ

Fa in a‘raḍū faqul anżartukum ṣā‘iqatam miṡla ṣā‘iqati ‘ādiw wa ṡamūd(a).

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