39:55
وَٱتَّبِعُوٓا۟ أَحْسَنَ مَآ أُنزِلَ إِلَيْكُم مِّن رَّبِّكُم مِّن قَبْلِ أَن يَأْتِيَكُمُ ٱلْعَذَابُ بَغْتَةً وَأَنتُمْ لَا تَشْعُرُونَ
wa-ittabiʿū aḥsana mā unzila ilaykum min rabbikum min qabli an yatiyakumu l-ʿadhābu baghtatan wa-antum lā tashʿurūna
Follow the best teaching sent down to you from your Lord, before the punishment suddenly takes you, unawares,
"And follow the best of that which is sent down to you from your Lord (i.e. this Qur’ân, do what it orders you to do and keep away from what it forbids), before the torment comes on you suddenly while you perceive not!"