Surah Al-Ma'arij 70:15

كَلَّآ ۖ إِنَّهَا لَظَىٰ

No! Indeed, it is the Flame [of Hell],

Translation: Saheeh International

Tafsir

Nay! — a refutation of his wish. Lo! for him it namely the Fire will be the Churning Fire lazā — a name for Hell so called because it churns its flames tatalazzā against the disbelievers

Excerpt from Tafsir al-Jalalayn, commentary on 70:15, via Quran.com. The reader has the full commentary and 9 more tafsirs.