Surah Al-Qasas (The Stories), Verse 53

وَاِذَا یُتْلٰی عَلَیْهِمْ قَالُوْۤا اٰمَنَّا بِهٖۤ اِنَّهُ الْحَقُّ مِنْ رَّبِّنَاۤ اِنَّا كُنَّا مِنْ قَبْلِهٖ مُسْلِمِیْنَ ۟

Wa izaa yutlaa 'alaihim qaaloo aamannaa biheee innahul haqqu mir rabbinaaa innaa kunnaa min qablihee muslimeen

“And when it is recited to them, they say: "We believe therein, for it is the Truth from our Lord: indeed we have been Muslims (bowing to Allah's Will) from before this.”

Quran 28:53 (Yusuf Ali Translation)