[safisoft]

Maimonides explains in detail that some mitzvot are not relevant to all times and places, while some mitzvot are always relevant to any time and place.

Well, the RAMBAM was not Moshe, but yes your point is well taken. The fact is ALL the mitzvot are valid, however not all are applicable. For example, I am a man, so the mitzvot regarding niddah except where I am addressed as a man do not apply to me.

As for the RAMBAM codifying the 613, that is not quite true, although he is credited with the 13 'I believes', and he did create a detailed list of 613 mitzvot - but he did not come up with it.

[Red Sea Swimmer]

A good book on this subject, which I refer to often, is...

"The Mitzvot - The Commandments and their Rationale"

by Abraham Chill.

(Keter Publishing House - Urim Publications, Jerusalem.)