The Holy Quran 18:91 — Surah Al-Kahf

Arabic text

كَذَٰلِكَ وَقَدْ أَحَطْنَا بِمَا لَدَيْهِ خُبْرًا

Translation

This is how it (his extensive travels) was. We surely had knowledge of everything that he possessed (Therefore, whatever We narrate to you is the absolute truth and not mere tales).

Tafsir (excerpt) — Tafsir Usmani

That is, the account given of Dhu al-Qarnayn's journeys to the east and west is in reality just so. All the means he had and all the circumstances he met there are encompassed by Our knowledge. Historians perhaps say something else here, but in truth [it was] only as much as has been stated. Some commentators have taken the meaning of “کذلک” (“thus”)

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