Surah Al-Haqqah 69:38
فَلَآ أُقْسِمُ بِمَا تُبْصِرُونَ
So I swear by what you see
Translation: Saheeh International
Tafsir
So indeed fa-lā lā is extra I swear by all that you see of creatures
Excerpt from Tafsir al-Jalalayn, commentary on 69:38, via Quran.com. The reader has the full commentary and 9 more tafsirs.