Quran 39:55 from Surah Az-Zumar on Divine Marvels.
وَٱتَّبِعُوٓاْ أَحۡسَنَ مَآ أُنزِلَ إِلَيۡكُم مِّن رَّبِّكُم مِّن قَبۡلِ أَن يَأۡتِيَكُمُ ٱلۡعَذَابُ بَغۡتَةٗ وَأَنتُمۡ لَا تَشۡعُرُونَ
English translation: And follow (the) best (of) what is revealed to you from your Lord before before [that] comes to you the punishment suddenly while you (do) not perceive
Transliteration: wa-ittabi'u ahsana ma unzila ilaykum min rabbikum min qabli an yatiyakumu al-'adhabu baghtatan wa-antum la tash'uruna