What are the connotations of the phrase "b'Etzem ha'Yom ha'Zeh"?
Ramban (on Pasuk 28): Literally it means on this very day, and it comes to teach us that, despite the intrinsic connection between the Yom-Tov and the Sefiras ha'Omer and the Minchah Chadashah mentioned earlier, the day itself is a Yom-Tov, irrespective of the Sefiras ha'Omer and the Korbanos. 1
Targum Yonasan: It is a hint that if we observe the above Mitzvos, we will merit to live and experience Shavu'os. 2
Why does the Pasuk insert the phrase "Chukas Olam be'Chol Moshvoseichem"?
Ramban and Seforno: Refer to 23:14:3:1*.