وَإِذْ تَأَذَّنَ رَبُّكُمْ لَئِن شَكَرْتُمْ لَأَزِيدَنَّكُمْ ۖ وَلَئِن كَفَرْتُمْ إِنَّ عَذَابِي لَشَدِيدٌ
And remember when your Lord proclaimed, "If you are grateful, I will surely increase you in favor; but if you deny, indeed, My punishment is severe."