And follow the best of what was revealed to you from your Lord [i.e., the Qur’ān] before the punishment comes upon you suddenly while you do not perceive,
Follow the Qur’ān, which is the best of what your Lord has revealed to His Messenger. Act on its instructions and avoid its prohibitions, before the punishment comes to you suddenly while you are unaware of it so as to prepare for it by repentance.