التفسير التبليغي
(مَا يَلْفِظُ مِنْ قَوْلٍ إِلَّا لَدَيْهِ رَقِيبٌ عَتِيدٌ) [He does not utter any word except that with him is an observer, ever-present.] (50:18)
Regarding the verse: (مَا يَلْفِظُ مِنْ قَوْلٍ إِلَّا لَدَيْهِ رَقِيبٌ عَتِيدٌ), the majority of the actions of the people of faith and certainty are internal (related to the heart): concern, or sorrow, or thought.
(رَقِيبٌ): An angel who observes him. (عَتِيدٌ): Ever-present, and he writes everything.
(مَا يَلْفِظُ مِنْ قَوْلٍ): Meaning, whatever he utters from his mouth, except that with him is an observer (رَقِيبٌ), a guardian (حَافِظٌ), ever-present (عَتِيدٌ), and constantly accompanying.
(عَتِيدٌ): Prepared and ready to write whatever he is commanded to record, be it good or evil.
(مَا يَلْفِظُ مِنْ قَوْلٍ إِلَّا لَدَيْهِ رَقِيبٌ عَتِيدٌ): So that the servant may know that he is neither neglected nor lost.
Source: التفسير التبليغي