Surah Al-'Adiyat 100:7

وَإِنَّهُۥ عَلَىٰ ذَٰلِكَ لَشَهِيدٌ

And indeed, he is to that a witness.

Translation: Saheeh International

Tafsir

and verily to that ingratitude of his he is a witness bearing witness against himself to his own actions.

Excerpt from Tafsir al-Jalalayn, commentary on 100:7, via Quran.com. The reader has the full commentary and 9 more tafsirs.