Surah An-Naba 78:21

إِنَّ جَهَنَّمَ كَانَتْ مِرْصَادًا

Indeed, Hell has been lying in wait

Translation: Saheeh International

Tafsir

Verily Hell lurks in ambush mirsādan in the sense of rāsidatan or mursidatan ‘lying in wait’

Excerpt from Tafsir al-Jalalayn, commentary on 78:21, via Quran.com. The reader has the full commentary and 9 more tafsirs.