And where does it say any of that?
Other than Deuteronomy 6:1? "These are the commands, decrees and laws the LORD your God directed me to teach you to observe in the land that you are crossing the Jordan to possess," Moses said that these are God ordained commands. The word 'torah' means law, and the torah is also used to describe all the books of the bible containing the Mosaic law, which includes but is not limited to the ten commandments, given to the people through Moses by God.
Exod. 24:12 also says “Come up to Me on the mountain and be there; and I will give you tablets of stone, and the law and commandments which I have written, that you may teach them.” Which means that the law, all of it, was given by God. Not just the 10 commandments. Exodus 24:18 says he stayed on the mountain receiving instruction for the law for 40 days and 40 nights.