What is the significance of the Levi and the Ger, Yasom and Almanah?
Rashi: The Levi
Rashi: As opposed to the previous two years, when the owner ate his Ma'aser Sheini in Yerushalayim.
Why does the Torah write "u'Ba ha'Levi"?
Rosh Hashanah, 12b: To teach us that, even though Ma'aser Sheini and Ma'aser Ani do not apply in the same year, Ma'aser Rishon applies every year. 1
See Torah Temimah, note 84.
What are the implications of "Ki Ein lo Cheilek ve'Nachalah imach"?
Rashi (in Sotah, 43b): It implies that the Levi does not receive Ma'aser from Hefker, 1 Leket, Shikchah and Pe'ah, since he already has an equal share in it.
Why does the Torah insert the (otherwise superfluous) words "asher bi'She'arecha"?
Sifri: To prohibit taking Ma'aser Ani (Ramba) 1 from Eretz Yisrael to Chutz la'Aretz.
According to the G'ra, it is a prohibiqtion against taking the Aniyim from Eretz Yisrael to Chutz la'Aretz. See Torah Temimah, note 86.
What does the Torah add the words "ve'Achlu ve'Save'u"?
Rashi: Because one is obligated to give each recipient sufficient to satisfy him (for one day). 1
Sifri: Half a Kav (twenty-four egg-volumes) of wheat and one Kav of barley. See Pe'ah, 8:5.
What is the significance of the juxtaposition of "Ve'achlu" to "asher bi'She'arecha"?
Oznayim la'Torah: To teach us that the Levi, Ger, Yasom and Almanah do not need to eat their respective Ma'asros in Yerushalayim.
