Tafsir of Al-Kahf 18:36

And perhaps he also frightened him with the Hour, so he said to him: "And I do not think the Hour will be established," meaning: existing in that which is to come. Thus, the 'establishing' (al-qiyam), which is one of the attributes of bodies, is a metaphor for existence and realization, though it flows in common usage like a reality.

"And if I am brought back to my Lord," by resurrection when it occurs, as you claim, "I will surely find," at that time, "a better than it," meaning: than this garden. Ibn al-Zubayr, Zayd ibn Ali, Abu Bahriya, Abu Ja'far, Shaybah, Ibn Muhaysin, Humayd, Ibn al-Mundhir, Nafi', Ibn Kathir, and Ibn Amir read it as "minhuma" (than both of them), using a dual pronoun. This is also how it appears in the codices of Makkah, Madinah, and Syria, meaning: from the two gardens.

"As a return," meaning: a place of returning and an outcome, due to the perishing of the first and the remaining of the other, according to your claim. This is a tamyiz (specifier) transformed from the subject, as Abu Hayyan has explicitly stated.

The extent of this greed and wicked oath is his belief that the Almighty only bestowed upon him what He bestowed in this world because of his own intrinsic merit and his honor in the sight of the Glorified One. This is like the Almighty’s statement in narration: "And if I am returned to my Lord, indeed, I will have the best with Him." He did not know that this was a gradual leading to ruin (istidraj).

It is as if, due to the precedence of that which is difficult for him to part with—namely the garden which he thought would never perish—the word "brought back" (ruddittu) was used here. And due to its absence in that which will come later, if Allah wills, in the mentioned verse of Surah Ha-Mim, the word "returned" (ruji'tu) was used. Let this be contemplated.