Quran 10:104 from Surah Yunus on Divine Marvels.
قُلۡ يَٰٓأَيُّهَا ٱلنَّاسُ إِن كُنتُمۡ فِي شَكّٖ مِّن دِينِي فَلَآ أَعۡبُدُ ٱلَّذِينَ تَعۡبُدُونَ مِن دُونِ ٱللَّهِ وَلَٰكِنۡ أَعۡبُدُ ٱللَّهَ ٱلَّذِي يَتَوَفَّىٰكُمۡۖ وَأُمِرۡتُ أَنۡ أَكُونَ مِنَ ٱلۡمُؤۡمِنِينَ
English translation: Say O (mankind) (O) mankind If you are in doubt of my religion then not I worship those whom you worship besides Allah besides Allah besides Allah but I worship Allah the One Who causes you to die And I am commanded that I be of the believers
Transliteration: qul yaayyuha al-nasu in kuntum fi shakkin min dini fala a'budu alladhina ta'buduna min duni al-lahi walakin a'budu al-laha alladhi yatawaffakum wa-umir'tu an akuna mina al-mu'minina