Quran 26:189 from Surah Ash-Shu'araa on Divine Marvels.
فَكَذَّبُوهُ فَأَخَذَهُمۡ عَذَابُ يَوۡمِ ٱلظُّلَّةِۚ إِنَّهُۥ كَانَ عَذَابَ يَوۡمٍ عَظِيمٍ
English translation: But they denied him so seized them (the) punishment (of the) day (of) the shadow Indeed it was (the) punishment (of) a Day Great
Transliteration: fakadhabuhu fa-akhadhahum adhabu yawmi al-zulati innahu kana adhaba yawmin azimin