Surah Maryam 19:64

وَمَا نَتَنَزَّلُ إِلَّا بِأَمْرِ رَبِّكَ ۖ لَهُۥ مَا بَيْنَ أَيْدِينَا وَمَا خَلْفَنَا وَمَا بَيْنَ ذَٰلِكَ ۚ وَمَا كَانَ رَبُّكَ نَسِيًّا

[Gabriel said], "And we [angels] descend not except by the order of your Lord. To Him belongs that before us and that behind us and what is in between. And never is your Lord forgetful -

Translation: Saheeh International

Tafsir

When the Revelation did not come for a number of days the Prophet s said to Gabriel ‘What prevents you from visiting us more often than you do?’ and so the following was revealed And We do not descend except by the commandment of your Lord. …

Excerpt from Tafsir al-Jalalayn, commentary on 19:64, via Quran.com. The reader has the full commentary and 9 more tafsirs.