What are the connotations of "Sh'mor Veshama'ta"? See Torah Temimah, note 109.
Rashi: "Sh'mor" refers to Mishnah and "Shama'ta" to observing the Mitzvos - One must first learn and take care not to forget 1 one's learning; otherwise, it is impossible to keep the Mitzvos. 2
Menachos, 81b: The Torah writes "Sh'mor" to obligate someone who undertakes to bring a Minchah without the loaves or a Shelamim without the Nesachim, to bring the Minchah with the loaves and the Shelamim with the Nesachim - even if he says that, had he known that he is obligated to do so, he would not have undertaken to bring the Korban. And it writes "Ve'shama'ta" to teach him not to get into the habit of doing so.
Sifri #1: 'If you will keep (the Mitzvos) a little, you will go on to hear (learn) a lot; and if you will keep everything that you hear, you will ultimately keep even what you did not hear. 3
Sifri #2: It teaches us that whoever does not learn will not keep. 4
Why does the Torah not mention 'Chukim and Mishpatim' or 'Eidos and Mitzvos', as it usually does?
Ramban: It deliberately mentions "... Eis Kol ha'Devarim" in order to include in the Mitzvah of "Sh'mor ve'Shama'ta" (compromise) and Lifnim mi'Shuras ha'Din (going beyond the letter of the law), 1 which we learn from "ha' Tov ve'ha'Yashar" (and which are an integral part of Torah and Mitzvos). 2
Refer to 12:18:4:1*.
In keeping with the Mishnah in Avos, 4:2 'Hevei Ratz le'Mitzvah Kalah ke'va'Chamurah'. Refer also to 6:18:1:1**.
Why does the Torah insert the (otherwise superfluous) word "eis Kol ha'Devarim"?
Rashi: To teach us that (seemingly) small Mitzvos should be just as dear to us as big ones. 1
Ramban: Refer to 12:28:2:1.
What is the difference between "ha'Tov" and "ha'Yashar"?
Rashi (acording to R. Akiva in the Sifri) 1 : "ha'Tov" means 'in the eyes of man' (bein Adam la'Chavero), 2 and "ha'Yashar", 'in the eyes of G-d' (bein Adam la'Makom).
Sifri (according to R. Yishmael): "ha'Tov" means 'in the Eyes of Hashem' and "ve'ha'Yashar", in the eyes of man'. 3
Ha'amek Davar: Refer to 12:28:5:1.
Why does the Torah write here "Ve'asisa ha'Tov ve'ha'Yashar", inverting the order in which it presents them above in Va'eschanan, 6:18 - "Ve'asisa ha'Yashar ve'ha'Tov ... "?
Why does the Torah add the (otherwise superfluous) words "ki Sa?aseh ha?Tov ve?ha?Yashar be'Einei Hashem Elokecha"?
Oznayim la'Torah: To teach us that if something is good and right in the Eyes of Hashem, then we are obligated to do it - even if we do not understand it.