Why does the Torah write "Matzos Ye'achel Es Shiv'as ha'Yamim," and not 'Matzos Tochelu ... '?
Oznayim la'Torah: To teach us that it is not a Mitzvah to eat Matzah throughout Pesach, as it is on the first night; only that one should see to it that Matzos are eaten, by not possessing Chametz. 1
Oznayim la'Torah: Similar to the first year, when it was a Mitzvah to eat Matzah on the first night, whereas on the subsequent six days they ate Matzah because their dough did not rise - but not because it was a Mitzvah.
What do we learn from the word, "Es [Shiv'as ha'Yamim]"?
What are the implications of the word "Lecha," in "v'Lo Yera'eh Lecha Chametz"?
Pesachim 5b: It implies that one may retain Chametz belonging to a Nochri or to Hekdesh. 1
See Torah Temimah, note 24.
Why does the Pasuk switch in the middle from "Chametz" to "Se'or"?
Beitzah 7b (citing Beis Hillel): To compare the Shi'ur of Se'or (sourdough) for which one is Chayav, to that of Chametz - namely, a k'Zayis. 1
According to Beis Shamai, the Shi'ur for Se'or (regarding Bal Yera'eh) is a k'Zayis, but for Chametz, a Koseves (a large date). Refer to 12:15:2.1:1*; and see Torah Temimah here, note 25.
Regarding the prohibition of 'Bal Yera'eh' of Se'or, why did the Torah write "b'Vateichem" in 12:19; whereas here it writes "b'Chol Gevulecha"?
Pesachim 5b: To compare Gevulim to Batim with regard to transgressing Bal Yera'eh and Bal Yimatzei, 1 Bal Yatmin, and Bal Yekabel Pikdonos 2 on the Chametz of Nochrim.
Mechilta: To teach us that, just as the Chametz in one's house is under one's jurisdiction, so too, is one only Chayav regarding 'Gevulim' if the Chametz is under one's jurisdiction (Torah Temimah - This excludes cases in which, a. the Yisrael did not accept responsibility; b. Chametz of a Yisrael that one deposited by a Nochri, over which the Nochri has taken responsibility; c. Chametz on which a ruin fell and which one is unable to destroy.
The previous Pasuk wrote, "Shiv'as Yamim Tochal Matzos" (13:6), with "Matzos" written Chaser (without a Vav). Why does the current Pasuk write a. "Ye'achel" (in the passive), and b. "Matzos" Malei (with a Vav)?
Divrei Eliyahu: The Torah hints at the Minhag cited by the Rema (OC 429) - to buy wheat to distribute to the poor for the needs of Pesach, based on the Yerushalmi (Bava Basra Sof 1:4). First the Torah commands everyone to eat, then it adds a. to ensure that Matzah will be eaten - the poor will be able to eat as well, b. and it writes "Matzos" in full 1 - a sign that one should give the poor sufficient to satiate them. 2
Divrei Eliyahu: And the former is written Chaser - because for oneself, one should be satisfied with the basic amount of food that one needs to subsist.
Divrei Eliyahu: As the Torah writes in Parshas Ki Savo, "v'Achelu bi'She'arecha v'Savei'u" (Devarim 26:12).
