Was Moshe Rabbeinu obligated in mitzvos during the two periods of 40 days that he spent on Mount Sinai? Did he keep mitzvos (whether obligated to or not) during that time?
I ask because the Torah says (Devarim 9:9):
"I remained on the mountain forty days and forty nights; I neither ate bread nor drank water;"
And the Gemara says (Bava Metzia 86b):
R. Tanhum b. Hanilai said: One should never break away from [the] custom [of the place he is in]. For behold, Moses ascended on High and ate no bread, whereas the Ministering Angels descended below and ate bread.
This got me thinking: angels are also not (obligated in|capable of) mitzvos. So perhaps Moshe was not obligated to, and didn't, keep mitzvos then, either. Also, there are many mitzvos/halachos involved with eating, e.g. Kiddush, me'ah brachos, seudas Yom Tov (he was up there on Rosh Hashana, so apple in honey too, right? =)). If Moshe didn't eat, does that mean he wasn't fulfilling those mitzvos?
As has been pointed out in the comments and answers, much of the Torah and many of the mitzvos had not yet been given at the time Moshe was on the mountain.
So, to clarify my question: I'm not discussing which mitzvos Moshe was obligated in at that period of time (while not on the mountain).
I wish to know if Moshe kept those mitzvos he was obligated in, as well as if he kept mitzvos that he wasn't (yet) obligated in, as did the Patriarchs.
Even more specifically, I'm not looking for "svaros", but rather for sources in Rabbinic literature that mention or discuss this.