Surah Al-Kahf 18:90

حَتَّىٰٓ إِذَا بَلَغَ مَطْلِعَ ٱلشَّمْسِ وَجَدَهَا تَطْلُعُ عَلَىٰ قَوْمٍ لَّمْ نَجْعَل لَّهُم مِّن دُونِهَا سِتْرًا

Until, when he came to the rising of the sun [i.e., the east], he found it rising on a people for whom We had not made against it any shield.

Translation: Saheeh International

Tafsir

until when he reached the rising of the sun the place where it rises he found it rising on a folk namely Negroes zanj for whom We had not provided against it that is against the sun any form of cover in the way of clothing or roofing as their land could not support any structures; …

Excerpt from Tafsir al-Jalalayn, commentary on 18:90, via Quran.com. The reader has the full commentary and 9 more tafsirs.