What basic Halachah is this Pasuk coming to teach us?
Rashi #1: It teaches us that the prohibition is confined to treating the crops as an owner, but does not extend to eating them. 1
Provided one makes them Hefker. See Sifsei Chachamim.
What are the implications of the words "Shabbas ha'Aretz Lachem le'Ochlah"?
Rashi: They imply that one may only eat from what is Hefker, 1 but not from what is guarded.
Ramban and Moshav Zekenim: The land resting mentioned earlier in Pasuk 4 and the produce of the Shabbos year, shall be for you all as livelihood, for you, your servants, your animals and Chayos of the land.
Yerushalmi, Shevi'is, 7:1: The produce of the land shall be for all your personal uses - for eating, drinking, anointing and dyeing. 2
What are the implications of the word "Lachem?
Yerushalmi, Shevi'is, 7:1: Refer to 25:6:2:3.
Sifra: 'For you', but not for Nochrim. 1
What are the implications of the word "le'Ochlah"?
Sukah, 40 a & b): "le'Ochlah", 've'Lo li'Refu'ah'. See Torah Temimah, and note 23.
Bechoros, 12b: "le'Ochlah" exempts animals purchased with money of Shevi'is from the Bechorah
Why does the Torah need to specify "L'cha u'le'Avdecha vela'Amasecha
Rashi: To teach us that the Heter to eat Sh'mitah produce extends to the wealthy owner, who may eat it just like his servants and maidservants. Otherwise, since the Torah writes in Mishpatim, Sh'mos 23:11 "ve'Achlu Evyonei Amecha", we would have thought that only the poor are permitted to eat it. 1
See Sifsei Chachamim. Riva: And "ve'Achlu Evyonei Amecha" teaches us that only the poor may eat even after the time of Bi'ur.
Who are "Sechircha" and "Toshavcha" referring to?
Rashi: They refer to Nochrim 1 (Geirim Toshavim and guests respectively
Sifsei Chachamim: It cannot refer to Avadim Ivrim (during the first six years and after they have had their ears pierced, respectively)
QUESTIONS ON RASHI
Rashi writes that also the wealthy may eat. One opinion (in Yerushalmi Shevi'is 9:8) forbids Ashirim after Bi'ur. How will he explain the Pasuk?
Moshav Zekenim citing the Sifra: Some say that the Pasuk discusses before Bi'ur, and the argument is about after Bi'ur.