Why does Moshe use the expression "Va'eschanan" rather than 'Va'espalel'?
Rashi #1: 'Chinun' is an expression of 'a free gift' 1 - Moshe was not asking Hashem to answer him as a reward for his good deeds. Even though Tzadikim are not short of good deeds, they only ask Hashem for free gifts (Hashem's Chesed). 2
Rashi #2 (citing the Sifri), Ramban Targum Onkelos and Targum Yonasan: It is a Lashon of Tefilah (one of the ten expressions of Tefilah, 'Techinah' which translates as 'supplication'
What is the connection between this Parshah and the previous one?
Ramban: With reference to the "ba'Eis ha'Hi" in Pasuk 21, where, after discussing the defeat of Sichon and Og, Moshe prepared Yehoshua not to be afraid of the Cana'anim, he adds that he (Moshe) will not merit to enter Eretz Yisrael, since, when he prayed, Hashem did not answer his prayers, but ordered him to strengthen Yehoshua.
What is the significance of "ba'Eis ha'Hi"?
Rashi and Ramban #2: After he had defeated Sichon and Og (nations that Hashem gave to Yisrael, and had distributed their land to two of the tribes - Ramban), 1 Moshe thought that perhaps Hashem had pardoned him and released the Neder (prohibiting him from entering Eretz Yisrael). 2
Rashbam: It implies that Moshe did not Daven immediately when the decree was issued. 5
Ramban: See 1:37.
Only his Tefilah that Hashem did answer (See Bamidbar 27:12 and 16-17), to which Moshe now will refer in Pasuk 28.
Rashbam: Due to the Mishnah in Avos, 4:18 'Al Tish'al lo be'Sha'as Nidro'. And as a reward (for his paytience), Hashem told him that, whereas other Meisim go to Gehinom, he would 'ascend to the top of Pisgah' and view the land from there.
Why did Moshe add the word "Leimor"?
Rashi: This is one of three locations 1 where Moshe told Hashem that he refuses to leave Him until He informs him whether He will fulfill his request or not.
Why did Moshe mention his (unanswered) Tefilah here?