Salaamun Alaykum.

This is a reminder type of disclosure, plus a logical argument to support the 3ilm.

I found a clear reference where the Quran allows directly to see that Lam must mean against or it contradicts other Ayat:

(17:7) إِنْ أَحْسَنتُمْ أَحْسَنتُمْ لِأَنفُسِكُمْ ۖ وَإِنْ أَسَأْتُمْ فَلَهَا ۚ

Here the first Lam indicates “for” yourselves and the second clearly indicates “against”. Some translators said it means “then it’s [also] for yourselves” .

But this clearly contradicts with two other Ayat conveying a similar point:

(41:46) مَّنْ عَمِلَ صَـٰلِحًۭا فَلِنَفْسِهِۦ ۖ وَمَنْ أَسَآءَ فَعَلَيْهَا ۗ

(45:15) مَنْ عَمِلَ صَـٰلِحًۭا فَلِنَفْسِهِۦ ۖ وَمَنْ أَسَآءَ فَعَلَيْهَا ۖ

Here the classical usage of 3layna is conveying the meaning of “against” and the ruling of these Ayat clearly indicate that good things are for the Nafs and bad things are against it.

So in

(17:7) إِنْ أَحْسَنتُمْ أَحْسَنتُمْ لِأَنفُسِكُمْ ۖ وَإِنْ أَسَأْتُمْ فَلَهَا ۚ

we have clear conceptual evidence that Lam has the meaning of “against”. Otherwise the translation would clearly be disaligned from the other two Ayat delivering the same ruling.

Yes I know it was mentioned in [YT125;01:00:43], but I totally forgot about it and was in anger to not being able to provide the linguistic basis and argument for the usage of Lam to undeniable mean “against”.

May this reminder benefit us all!

Salaamun Alaykum!