Surah Al-Mursalat 77:30

ٱنطَلِقُوٓا۟ إِلَىٰ ظِلٍّ ذِى ثَلَـٰثِ شُعَبٍ

Proceed to a shadow [of smoke] having three columns.

Translation: Saheeh International

Tafsir

Depart to a triple-forked shadow — this is the smoke of Hell which as it rises splits into three parts because of its magnitude —

Excerpt from Tafsir al-Jalalayn, commentary on 77:30, via Quran.com. The reader has the full commentary and 9 more tafsirs.