Surah An-Naba 78:23

لَّـٰبِثِينَ فِيهَآ أَحْقَابًا

In which they will remain for ages [unending].

Translation: Saheeh International

Tafsir

to remain lābithīna is an implied circumstantial qualifier in other words their remaining therein will be decreed to be therein for ages for endless epochs ahqāb is the plural of huqb

Excerpt from Tafsir al-Jalalayn, commentary on 78:23, via Quran.com. The reader has the full commentary and 9 more tafsirs.