Surah Qaf 50:18

مَّا يَلْفِظُ مِن قَوْلٍ إِلَّا لَدَيْهِ رَقِيبٌ عَتِيدٌ

He [i.e., man] utters no word except that with him is an observer prepared [to record].

Translation: Saheeh International

Tafsir

he does not utter a word but that there is beside him a watcher a guardian who is ready present both raqībun ‘watcher’ and ‘atīdun ‘ready’ are meant to indicate the dual.

Excerpt from Tafsir al-Jalalayn, commentary on 50:18, via Quran.com. The reader has the full commentary and 9 more tafsirs.