What is the meaning of the word "Tichru"?
Rashi: It means "You shall purchase". 1
Rashi: As in Vay'chi Bereishis, 50:5 - as the Gemara explains in Rosh Hashanah, 26a.
What kind of food was Hashem referring to?
Targum Onkelos: Grain (Raw grain, since Bishul Akum was prohibited - Targum Yonasan). 1
Was it a Mitzvah to purchase food and water from Edom?
Rashi (on Pasuk 7): Yes. Refer to 2:7:2:1.
Ramban: No! What the Pasuk means is that, if they want to taste the fruit of Edom or drink their water, then they may only do so if they pay for them in full, at whatever price they ask. 1
Ramban: As implied by the word "me'Itam". In fact, Yisrael carried out these instructions, as Pasuk 29 indicates.
Why does the Torah insert the (otherwise superfluous) phrase "ve'Gam Mayim Tichru me'Itam ... "? Why does it not write simply 'Ochel u'Mayim Tishb'ru me'Itam'?
Oznayim la'Torah #1: To teach Yisrael that, even though, whereas food needs to be prepared, water is freely available, they should make a point of paying the B'nei Eisav 1 for it.
Oznayim la'Torah #2: To teach Yisrael that, even if the B'nei Eisav gave them permission to dig wells and drink the water - leaving the wells in their (the B'nei Eisav's) possession, they should nevertheless pay for the water.
Why does the Torah add the (otherwise superfluous) words "Va'achaltem" and "u'Shesisem"?
Oznayim la'Torah #1 (citing the M'lo ha'Omer): To assure them that - since the B'nei Eisav were afraid of them, they could be rest assured that the food and water that they sold them was not poisoned.
Oznatyim la'Torah #2 (citing the K'sav ve'ha'Kabalah: It implies they they should purchase only sufficient to eat and drink, but not to take with them, just as Hashem had fed them until now, so too, would He continue to feed them, in which case it was unnecessary to buy provisions for the journey.
Oznayim la'Torah: #3: To counter their complaints about the Manna - and presumably, about the water, 1 because, when they would now partake of regular food and water, they would realize just how superior the Manna and the water of the well, which enjoyed Divine blessing, really were.
See Oznayim la'Torah DH 'Ochel Tishb'ru #1.
Why did Hashem insist that Yisrael pay for the food and water that they purchased from the B'nei Eisav?*
Rashi (in Chukas): Refer to Bamidbar, 20:17:2:1 and note. 1
Oznayim la'Torah: In order to avoid building a relationship with them. 2
Yerushalmi Shabbos, 1:4: We learn from here that one should benefit one's enemy via food or money. 3
See also Oznayim la'Torah on Pasuk 7.
Like Ya'akov did when he met Eisav after he fld from Lavan. See Vayishlach Bereishis, 33:12-14.
See Torah Temimah, citing Yerushalmi, Ibid., and note 2.
