Surah Al-Qasas 28:53

وَإِذَا يُتْلَىٰ عَلَيْهِمْ قَالُوٓا۟ ءَامَنَّا بِهِۦٓ إِنَّهُ ٱلْحَقُّ مِن رَّبِّنَآ إِنَّا كُنَّا مِن قَبْلِهِۦ مُسْلِمِينَ

And when it is recited to them, they say, "We have believed in it; indeed, it is the truth from our Lord. Indeed we were, [even] before it, Muslims [i.e., submitting to Allāh]."

Translation: Saheeh International

Tafsir

And when it is recited to them the Qur’ān they say ‘We believe in it. It is indeed the Truth from our Lord. Lo! even before it we had submitted’ we affirmed God’s Oneness.

Excerpt from Tafsir al-Jalalayn, commentary on 28:53, via Quran.com. The reader has the full commentary and 9 more tafsirs.