Tafsir of Al-Kahf 18:89

"Then he followed a way."

It is read as maṭlaʿ (with a fatḥah on the lām), which is a verbal noun (maṣdar). The meaning is: he reached the place of the rising of the sun, similar to the saying: "As if the trailing of the winds [dragging] their tails..." meaning: as if the traces of the trailing of the winds.

"Upon a people..." It is said: They are the Zanj.

"And a covering..." Meaning: buildings. Kaʿb said: Their land does not support buildings, and it has tunnels. When the sun rises, they enter them; when the day rises high, they go out to their livelihoods.

Another reports: I traveled until I passed China and asked about these people. It was said: "Between you and them is a journey of a day and a night." I reached them, and one of them would spread one ear and wear the other. I had a companion who knew their language, and they said to him: "Have you come to see how the sun rises?" While we were thus, we heard a sound like a clanging, and I fainted. When I regained consciousness, they were wiping me with oil. When the sun rose over the water, it appeared above the water like oil, and they brought it into a tunnel of theirs. When the day rose high, they went out to the sea, caught fish, and threw them into the sun, and it cooked for them.

It is also said: The "covering" refers to clothing. Mujahid said: Those who do not wear clothes among the blacks at the rising of the sun are more numerous than all the people of the earth.

"Thus..." Meaning: The affair of Dhu al-Qarnayn is thus, as we have described it, to magnify his status.

"And We have encompassed in knowledge what he had..." Of soldiers, equipment, and the means of kingship.

It is said: We did not provide them with a covering other than it, like the covering We provided for you—mountains, fortresses, buildings, shelters of every kind, and clothing of every sort.

It is said: He reached the rising of the sun in the same manner he reached its setting.

It is said: It rises upon a people like the tribe upon whom it sets, meaning they are disbelievers like them, and their judgment is like their judgment: he punishes those who remain in disbelief and shows kindness to those who believe among them.

"Then he followed a way. Until, when he reached between the two barriers, he found beside them a people who could hardly understand [any] speech."