Al-Qasas 28:49

قُلْ فَأْتُوا۟ بِكِتَـٰبٍ مِّنْ عِندِ ٱللَّهِ هُوَ أَهْدَىٰ مِنْهُمَآ أَتَّبِعْهُ إِن كُنتُمْ صَـٰدِقِينَ

Qul fatū bikitābin min ʿindi l-lahi huwa ahdā min'humā attabiʿ'hu in kuntum ṣādiqīna

Say, "Then bring a scripture from Allāh which is more guiding than either of them that I may follow it, if you should be truthful."