When does the Sh'mitah year begin?
Why does the Torah insert the (otherwise superfluous) word "u'va'Shanah ha'Shevi'is"?
Sifra: To teach us that (in certain regards) thirty days (one month) before Rosh Hashanah is considered a year, and that consequently, the Dinim of Sh'mitah of 'B'nos Shu'ach' (a species of white fig), takes place in the second year of the Sh'mitah cycle, 1 seeing as the fruit is only ready to pick in the third year. 2
Why does the Pasuk use the expression "Shabbas Shabbason"?
Seforno: To add preparatory Malachos 1 to the prohibition.
Oznayim la'Torah: With reference to the two distinct kinds of Melachah that are forbidden in the Sh'mitah
What is "la'Aretz" referring to?
Rashi and Seforno: It refers to the fields and vineyards - with reference to the Melachos that pertain to them, such as planting and reaping. 1
Digging pits per se (and building) are not prohibited during the Sh'mitah (Sifsei Chachamim).
Why does the Torah insert the words "Shabbos la'Hashem"?
Sifra: The Torah writes "Shabbos la'Hashem" by Sh'mitah and by Shabbos Bereishis in Yisro, Sh'mos, 20:10, to teach us that, just as Shabbos Bereishis is a testimony that Hashem created the world, so too, is Sh'mitah a testinoy that He owns it. 1
See also 'ha'Torah ve'ha'Mitzvah'.
What is the meaning of "Karm'cha Lo Tizmor"?
Rashi, Targum Onkelos 1 and Targum Yonasan: It means "Do not prune your vineyard.
See Sifsei Chachamim. Targum Onkelos translates it as 'Lo Tichsach' - as is Yeshayah, 32:12, and in Tehilim, 80:17.
Seeing as Pruning is incorporated in planting, and harvesting grapes, in harvesting corn, why does the Torah find it necessary to insert 'Zemirah' and 'Betzirah'?