Surah Al-Mu'minun 23:9

وَٱلَّذِينَ هُمْ عَلَىٰ صَلَوَٰتِهِمْ يُحَافِظُونَ

And they who carefully maintain their prayers -

Translation: Saheeh International

Tafsir

And who are watchful of their prayers may be read as plural salawātihim ‘their prayers’ or singular salātihim ‘their prayer’ observing them at their appointed times.

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