Quran 39:55 — The Throngs (Al-Zumar)

وَاتَّبِعوا أَحسَنَ ما أُنزِلَ إِلَيكُم مِن رَبِّكُم مِن قَبلِ أَن يَأتِيَكُمُ العَذابُ بَغتَةً وَأَنتُم لا تَشعُرونَ

And follow the best path that is pointed out for you by your Lord, before the retribution overtakes you suddenly when you least expect it.

[39:54] You shall obey your Lord, and submit to Him totally, before the retribution overtakes you, then you cannot be helped.

[39:56] Lest a soul may say, "How sorry I am for disregarding GOD's commandments; I was certainly one of the mockers."