Surah As-Saffat, ayah 157

فَأۡتُواْ بِكِتَٰبِكُمۡ إِن كُنتُمۡ صَٰدِقِينَ ١٥٧

Fa tū bikitābikum in kuntum sādiqīn

Then produce your scripture, if you should be truthful.