Question

Hello Rabbi,
I’ve read several times in the Rabbi’s articles that the Rabbi says that the reason the Torah wrote the prohibition against murder, for example, or any such interpersonal prohibition, is because it contains religious value, and that this religious value is not connected at all to moral value (because these are different systems of law). I wanted to ask: according to this, why did the Sages phrase things several times throughout the Talmud as “why do I need a verse if reason alone would tell me so”? That makes sense according to the common approach (that the Torah deals at least also with moral values), because if something is obvious by reason, there is no reason to state it in the Torah. But according to your approach, what is the source at all for logical reasoning in obligations or commandments? After all, this is a different value system that does not operate according to ordinary human logic.
I hope the question was clear. Thanks.