What are the implications of "Eileh ha'Mitzvos asher Tzivah Hashem es Moshe ... "?
Targum Yonasan and Shabbos, 104a: It implies that the Mitzvos listed until here are those that Hashem commanded Moshe and that nobody (no Navi - Shabbos) has the authority to add to them. 1
Yerushalmi Shabbos, 13:3: "Eileh ha'Mitzvos" implies that if one does not perform the Mitzvos in the manner prescribed by the Torah, they are not Mitzvos. 2
What is the significance of the fact that 'Hashem commanded Moshe to teach Yisrael ... '?
Da'as Zekenim and Hadar Zekenim: To teach us that the Shali'ach was worthy to be teach Yisrael, and Yisrael were worthy - their merit caused him [to reach his awesome closeness to Hashem. 1
Refer to Shemos 32:7:3:1 and note]. See also Torah Temimah, note 219.