Surah Al-Qasas (The Stories), Verse 49

قُلْ فَاْتُوْا بِكِتٰبٍ مِّنْ عِنْدِ اللّٰهِ هُوَ اَهْدٰی مِنْهُمَاۤ اَتَّبِعْهُ اِنْ كُنْتُمْ صٰدِقِیْنَ ۟

Qul faatoo bi Kitaabim min 'indil laahi huwa ahdaa minhu maaa attabi'hu in kuntum saadiqeen

“Say: "Then bring ye a Book from Allah, which is a better guide than either of them, that I may follow it! (do), if ye are truthful!"”

Quran 28:49 (Yusuf Ali Translation)