"Torah" or system of ethics-beliefs superior to what God came up with vis-a-vis Moses at Sinai. Well, since this is impossible, then perhaps the solution is to say that Jesus' teachings are not superior to the Mosaic Law. But they seem to us to be superior. But perhaps this is circular reasoning; we find them superior because we are Christians and have been taught them. But Rabbi Herz claims that the golden rule comes from the Torah (Liv. 19:18), so he admits the absolute superiority of Jesus' basic ethical premise but claims that it came in the Hebrew Torah long before Jesus]. Then Jesus was just repeating concepts already familiar to the Jews; e.g. Hillel. But Jesus does not just state the golden rule; his system is complex, intricate, sophisticated, vast. He did not utter just the one statement found in Liv. 19:18. So where did his other sayings come from; especially the Sermon of the Mount? Again, if he is only a man he is more advanced in terms of ethical conceptions and propositions than YHWH! In my opinion if you conclude that indeed the decalogue was given to Moses by God, then it follows from internal evidence, which is to say the teachings and system of Jesus, that Jesus was God or related to God in some way; for instance God's Holy Wisdom, or as with Ptath in the Egyptian system, God's "tongue."
Finally, Jesus presented a system which went beyond making men truly moral --spotless of sin-- but, more, restoring men to their pre-fallen state(1), and here the issue lies, because it seems probable that only God could inaugurate such a system -- unless you wish to take the argument that Jesus' system does not in fact restore man to his pre-fallen state but only claims to. But Judaism does not even make this claim for the Torah.
(1) But if man did not Fall, then what was I restored to? The Book of Adam and Eve (can't read)