Surah Al-Imran, ayah 20

فَإِنۡ حَآجُّوكَ فَقُلۡ أَسۡلَمۡتُ وَجۡهِيَ لِلَّهِ وَمَنِ ٱتَّبَعَنِۗ وَقُل لِّلَّذِينَ أُوتُواْ ٱلۡكِتَٰبَ وَٱلۡأُمِّيِّـۧنَ ءَأَسۡلَمۡتُمۡۚ فَإِنۡ أَسۡلَمُواْ فَقَدِ ٱهۡتَدَواْۖ وَّإِن تَوَلَّوۡاْ فَإِنَّمَا عَلَيۡكَ ٱلۡبَلَٰغُۗ وَٱللَّهُ بَصِيرُۢ بِٱلۡعِبَادِ ٢٠

Fa in hājjūka faqul aslamtu wajhiya lillāhi wamanit-taba'ani waqul lilladhīna ūtul-kitāba wal-ummiyyina a'aslamtum fa in aslamū faqadihtadaw wwa in tawallaw fa innamā 'alaykal-balāghu wallāhu basīru bil-'ibād

So if they argue with you, say, "I have submitted myself to Allāh [in Islām], and [so have] those who follow me." And say to those who were given the Scripture and [to] the unlearned,¹¹⁹ "Have you submitted yourselves?" And if they submit [in Islām], they are rightly guided; but if they turn away - then upon you is only the [duty of] notification. And Allāh is Seeing of [His] servants.