Al-Ma'idah 5:43

Wakayfa yuhakkimoonaka waAAindahumu attawratufeeha hukmu Allahi thumma yatawallawna minbaAAdi thalika wama ola-ika bilmu/mineen

But how is it that they come to you for judgement while they have the Torah, in which is the judgement of Allāh? Then they turn away, [even] after that; but those are not [in fact] believers.

How do they ask you to judge while the Torah is with them, having the ruling of Allah? Still, they turn away, after all that. They are no believers.