Surah Al-Mujadila 58:21

كَتَبَ ٱللَّهُ لَأَغْلِبَنَّ أَنَا۠ وَرُسُلِىٓ ۚ إِنَّ ٱللَّهَ قَوِىٌّ عَزِيزٌ

Allāh has written [i.e., decreed], "I will surely overcome, I and My messengers." Indeed, Allāh is Powerful and Exalted in Might.

Translation: Saheeh International

Tafsir

God has inscribed in the Preserved Tablet or it means He has decreed ‘I shall assuredly prevail I and My messengers’ by means of definitive proof or the sword. Truly God is Strong Mighty.

Excerpt from Tafsir al-Jalalayn, commentary on 58:21, via Quran.com. The reader has the full commentary and 9 more tafsirs.