Tafsir of Al-Kahf 18:76

(He said) i.e., Moses, peace be upon him: (If I ask you about anything) that you perform of the marvelous deeds, (after it) i.e., after this time or after this matter, (then do not keep me as a companion). Isa and Ya'qub read (fala tas-habni) with the ta opened, from suhba, meaning: do not be my companion. It is also narrated from Isa (fala tus-hibni) with the ta dammaed and the ha kasraed, from as-habahu; Sahl narrated it from Abu Amr, meaning: do not take me as a companion for yourself, nor make me your companion. Some estimate the second object to be "your knowledge," but this is not strong.

Al-A'raj read (fala tusaahibanni) with the ta and ba opened and the nun doubled; the intended meaning is the intensive form of prohibition, i.e., do not be my companion at all. This supports the view that the prohibition in what lacks emphasis is one of prohibition [haram], and the intention behind it is resolve in leaving and separating, not a concession in the sense of: "If I ask you again, you are permitted to abandon my companionship."

(You have reached an excuse from Me) i.e., you have found an excuse on my part. Al-Nawawi said: The meaning is: You have reached the limit for which you are excused in parting from me, as I have contradicted you time after time. It is authentic from the Prophet, peace be upon him, that he said: "May Allah’s mercy be upon us and upon Moses; had he been patient with his companion, he would have seen wonders, but he was seized by a sense of blame regarding his companion, so he said that."

Nafi' and 'Asim read (min ladunni) with a light nun, which is an argument against Sibawayh in his prohibition of that. The majority hold that the nun of protection (nun al-wiqaya) was deleted, while the original kasraed nun was kept, which is the standard analogy in nouns that are annexed [genitive construct], as they are not joined by the nun of protection, like watani (my nation) and maqami (my station). It is said: It is possible that the mentioned nun is the nun of protection, and that the noun annexed is lad without a nun, which is a dialect for ladun, so there is no deletion at all. This was countered by the fact that the nun of protection only occurs on that which is built upon sukun to protect it from a kasra, whereas lad without a nun is dammaed. This was refuted by saying there is no impediment to saying that it protected it from the removal of the damma. Shu'ba gave an ishmam (blending) of damma to the dal. It is narrated from 'Asim that he vocalized it with sukun. Mujahid said: "An erroneous mistake," perhaps intending the narration, for otherwise they have mentioned that lad with a fatha and sukun is a dialect for ladun. Isa read (udhran) with a damma on the dhal, and (udhri) with attribution to the ya of the first person was narrated from Abu 'Amr and Ubayy.