Quran 67:17 from Surah Al-Mulk on Divine Marvels.
أَمۡ أَمِنتُم مَّن فِي ٱلسَّمَآءِ أَن يُرۡسِلَ عَلَيۡكُمۡ حَاصِبٗاۖ فَسَتَعۡلَمُونَ كَيۡفَ نَذِيرِ
English translation: Or do you feel secure (from Him) Who (is) in the heaven not He will send against you a storm of stones Then you would know how (was) My warning
Transliteration: am amintum man fi al-samai an yur'sila alaykum hasiban fasata'lamuna kayfa nadhiri