Surah Al-Anbya 21:20
يُسَبِّحُونَ ٱلَّيْلَ وَٱلنَّهَارَ لَا يَفْتُرُونَ
They exalt [Him] night and day [and] do not slacken.
Translation: Saheeh International
Tafsir
They glorify Him night and day and they do not falter in it for it comes to them as naturally as breathing comes to us something which we can never be distracted from.
Excerpt from Tafsir al-Jalalayn, commentary on 21:20, via Quran.com. The reader has the full commentary and 9 more tafsirs.