Why does the Torah insert the phrase "Zos Toras ha'Nazir"?
Sifri: To incorporate a Nazir Olam in the Dinim regarding the Korbanos of a Nazir 1 - when he trims his hair each year.
See Torah Temimah, note 97.
What are the implications of "be'Yom M'los"?
Sifri Zuta; It implies that the Nazir must bring his Korbanos in the day and not in the night. 1
See also Tzav Vayikra, 7:38 and note 158.
What are the connotations of the word "Yavi Oso"? Who brings whom?
Rashi, Seforno and Targum Yonasan: It refers to himself 1 (He brings himself to the Kohen to perform the necessary ritual to release him from his Nezirus. 2
Rashbam: It means that the Nazir brings his Korban - as the Pasuk goes on to explain.
Sifri: It means that he - and not anybody else - brings himself to the Kohen . 3
Rashi: This is one of three locations where R. Yishmael explains 'Es' 'Oso' and 'Osam' in this way. The other two are in Emor Vayikra, 22:15 - "Ve'hisi'u Osam (es atzmam) Avon Ashmah" and in ve'Zos ha'Berachah Devarim, 34:6 - "Va'yikbor Oso (es Atzmo) ba'Gai".
Seforno: Since there is nobody superior to himself to whom to bring him. See Seforno. And that explains why the Torah only uses this Lashon in connection with a Tahor Nazir - not by a Tamei Nazir or by any other Tamei person.
See Torah Temimah, note 99.