Tafsir of Al-Kahf 18:38

{But He is Allah, my Lord}

The original form was lakin ana (but I). The hamza was deleted, and its vowel was transferred to the nun of lakin. The two nuns met, resulting in idgham (assimilation). Similar to this is the poet’s saying:

You cast glances at me, as if you are the guilty one, And you despise me, but I do not despise you.

Meaning: lakin ana (but I) do not despise you.

The pronoun huwa (He) is the pronoun of the "matter" (al-sha’n), and the "matter" is that Allah is my Lord. The sentence is the predicate of ana (I), and the referent returning to it is the ya of the pronoun.

Ibn Amir recited it with the affirmation of the alif of ana in both connection and pause, justifying this by the alif acting as a substitute for the deleted hamza. Others do not affirm it except in the pause. It is reported from Abu ‘Amr that he paused with a ha: lakin-hu.

It was also recited: {lakin huwa Allahu rabbi} with the nun quiescent and the omission of ana. Ubayy ibn Ka‘b recited: {lakin ana} according to the original form. In the recitation of ‘Abdullah [ibn Mas‘ud]: {lakin ana la ilaha illa huwa rabbi}.

If you ask: What is this a rectification (istidrak) of? I say: It is for his saying: {Have you disbelieved?}. He said to his companion: "You are a disbeliever in Allah, but I am a believer, a monotheist," just as you would say: "Zayd is absent, but ‘Amr is present."

{And why, when you entered your garden, did you not say, "What Allah willed; there is no power except in Allah"? If you see me less than you in wealth and children, then it may be that my Lord will give me [something] better than your garden and will send upon it a calamity from the sky, and it will become a smooth, dusty ground, or its water will become sunken [into the earth], so you would never be able to seek it.}