Surah Al-Inshiqaq 84:23

وَٱللَّهُ أَعْلَمُ بِمَا يُوعُونَ

And Allāh is most knowing of what they keep within themselves.

Translation: Saheeh International

Tafsir

and God knows best what they are amassing accumulating in their scrolls in the way of disbelief denial and evil deeds.

Excerpt from Tafsir al-Jalalayn, commentary on 84:23, via Quran.com. The reader has the full commentary and 9 more tafsirs.