Quran 28:49 from Surah Al-Qasas on Divine Marvels.
قُلۡ فَأۡتُواْ بِكِتَٰبٖ مِّنۡ عِندِ ٱللَّهِ هُوَ أَهۡدَىٰ مِنۡهُمَآ أَتَّبِعۡهُ إِن كُنتُمۡ صَٰدِقِينَ
English translation: Say Then bring a Book from Allah from Allah from Allah which (is) a better guide than both of them that I may follow it if you are truthful
Transliteration: qul fatu bikitabin min indi al-lahi huwa ahda min'huma attabi'hu in kuntum sadiqina