وَإِذۡ تَأَذَّنَ رَبُّكُمۡ لَئِن شَكَرۡتُمۡ لَأَزِيدَنَّكُمۡۖ وَلَئِن كَفَرۡتُمۡ إِنَّ عَذَابِي لَشَدِيدٞ
And when your Lord proclaimed, "If you are thankful, surely I will increase you, but if you are thankless My chastisement is surely terrible
Author: A. J. Arberry