Prove it.
In the end, the onus (burden) of proof is upon the one who believes it to be true to prove this. You.
But, there are radicals in other religions today who would say the same as you are here.
I, OTOH, say that both are wrong, and that the real God was not behind any barbaric Sura in the Koran nor behind and barbaric verse in the Pentateuch. Both are the result of mere men writing what they wanted to believe, and not form the hand of a loving God.
Yes, Moses did write some of the Pentateuch, but not all.