وَإِذۡ تَأَذَّنَ رَبُّكُمۡ لَئِن شَكَرۡتُمۡ لَأَزِيدَنَّكُمۡ ۖ وَلَئِن كَفَرۡتُمۡ إِنَّ عَذَابِى 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.’
لَئِن شَكَرۡتُمۡ لَأَزِيدَنَّكُمۡ
If you are grateful, I will surely increase you [in favor].
Allah could have said لَئِن تَشۡكُرُواْ, meaning “if you are grateful.” Had He expressed it with a present-tense verb, it could have implied ‘continuous gratitude.’ But He said لَئِن شَكَرۡتُمۡ: “If you are grateful…” There is a striking subtlety here. Gratitude is expressed with a past-tense verb, as if being grateful even once were enough. In contrast, with لَأَزِيدَنَّكُمۡ Allah stresses His promise of increase forcefully: “I will certainly, certainly, certainly increase you!” What is more, the use of the present-tense verb suggests that this increase happens again and again, many times over. Even if you are grateful just once, Allah may increase you many times over. Notice that what this increase consists of is not even stated. That is, Allah may bless you with countless favors, ones that come to mind and ones that never would. Thus the ayah draws a deeply moving contrast between the servant’s gratitude and Allah’s generosity.
Notice the emphasis: the lam (لَ) to make it stronger, then the heavy noon with shaddah (نَّ), the heaviest form of emphasis, doubled over.
وَلَئِن كَفَرۡتُمۡ إِنَّ عَذَابِى لَشَدِيدٌ
But if you deny, indeed, My punishment is severe.
And if you were to be ungrateful… Now it’s as though you don’t even deserve to be mentioned. You see?
لَأَزِيدَنَّكُمۡ, “I will increase you”: كُمۡ was referring to us. But when it comes to “I will take away from you, I will punish you,” you don’t even deserve to be mentioned.
If you forgot Allah, why should you be remembered?