Surah Al-Kahf, Verse 85

Tafsir of 18:85

His traveling and reaching the Place where the Sun sets (the West) فَأَتْبَعَ سَبَباً (So he followed a way.) Ibn `Abbas said that he followed different routes to achieve what he wanted. فَأَتْبَعَ سَبَباً (So he followed a way.) Mujahid said that he followed different routes, east and west. According to one report narrated from Mujahid, he said: سَبَباً (a way) means, "A route through the land." Qatadah said, "It means he followed the routes and landmarks of the earth." حَتَّى إِذَا بَلَغَ مَغْرِبَ الشَّمْسِ (Until, when he reached the setting place of the sun,) means, he followed a route until he reached the furthest point that could be reached in the direction of the sun's setting, which is the west of the earth. As for the idea of his reaching the place in the sky where the sun sets, this is something impossible, and the tales told by storytellers that he traveled so far to the west that the sun set behind him are not true at all. Most of these stories come from the myths of the People of the Book and the fabrications and lies of their heretics.…

Source: Ibn Kathir (Abridged)