Surah Al-Qamar 54:50

وَمَآ أَمْرُنَآ إِلَّا وَٰحِدَةٌ كَلَمْحٍۭ بِٱلْبَصَرِ

And Our command is but one, like a glance of the eye.

Translation: Saheeh International

Tafsir

And Our command for a thing which We want to bring into existence is but a single word like the twinkling of an eye in terms of speed and this is the saying of kun ‘Be’ whereat it comes into existence. His command when He wills a thing is just to say to it ‘Be’ and it is Q. 3682.

Excerpt from Tafsir al-Jalalayn, commentary on 54:50, via Quran.com. The reader has the full commentary and 9 more tafsirs.