Who is Moshe addressing?
Rashi and Seforno: Moshe is now speaking to the whole of Yisrael.
Ramban and Targum Yonasan: Moshe is still speaking to the tribe of Asher.
What is the meaning of "Barzel u'Nechoshes Min'alecha"?
Rashi #1: 'Iron and copper are your strength' - with reference to the strong tribes who dwell in Yisrael's border towns and prevent the enemy from entering. 1
Rashi #2: 'Your land is enclosed with mountains from which one can mine iron and copper - and the territory of Asher is the lock of Eretz Yisrael'. 2
Ramban #1: It refers to Asher, whose land is the lock of Eretz Yisrael, because it is the end (at the northern-western tip) of Eretz Yisrael. 3
Ramban #2: It refers to Asher, whose land is locked, in that no strangers will come to steal their oil - which they export all over the world in their merchant-ships.
Seforno: Refer to 33:2:1:1*. It means that no nations will enter your land or covet it - out of fear 4 - as if the land was protected with locks of iron and copper. 5
Targum Onkelos: It means 'Your habitat in the land will be strong like iron and copper'.
Targum Yonasan: It means 'Asher will be strong like iron and their feet will be as if they are shoed with copper to walk on the sharp rocks 6 .
Rosh, Da'as Zekenim and Hadar Zekenim (24, citing Seifer ha'Gan): This refers to sinews and bones, which are a bolt for the body like a lock for a door. Because they was constantly anointing themselves with oil, until their sinews and bones became strong like iron.
Riva: Refer to 33:24:1:10*.
Oznayim la'Torah (citing the S'fas Emes): If one wants to remain strong in one's old age - Refer to 33:25:3:1 - one must preserve one's Midos and one's strength in one's youth 'with iron and copper bolts', to prevent them from running amock.
Rashi: As if the land was locked and bolted with iron and copper locks and bolts.
Which explains why Moshe inserted this B'rachah with that of Asher.
Ramban: As in Yehoshua, 19:26 & 29, and in Shoftim, 1:31. See Ramban.
Seforno: As occurred throughout the days of Yehoshua and the elders.
See Na'ar Yonasan.
What is the meaning of "u'che'Yamecha Dav'echa"?
Rashi #1: 'And like the goodness of the days of your youth, so shall be the days of your old age - when one normally tends to decline'. 1
Rashi #2 (citing the Sifri): 'And according to your good days - on which you carry out the will of Hashem - the silver and gold will flow out from the nations who come to purchase the fruit with which your land is blessed.
Ramban #1: 'As long as you live, your oil will flow - to wash your feet'. 2
Ramban #2: 'Like your youth (early days in the land) so will be your old age (latter days) 3 - You will enjoy a long stay in the land in tranquilty and Simchah. 4
Seforno: Malchus Yisrael will continue steadily 5 from generation to generation without declining. 6
Targum Onkelos and Targum Yonasan: And you will be strong in your old age like the days of your youth'. CclSDF
Riva: Refer to 33:24:1:10*.
Rashi in Divrei ha'Yamim 1 7:31, Da'as Zekenim, Rosh and Hadar Zekenim (in Pasuk 24, citing Seifer ha'Gan): This is the result of anointing hemselves with oil in their youth. See Chulin 24b. Refer to 33:25:2:8. See also Sifsei Chachamim.
Ramban: As if the Torah had written 'Zav'echa' with a 'Zayin' - because 'Zayin' and 'Daled' are interchangeable, as in Yeshayah, 14:4. And we find this constantly from Lashon ha'Kodesh to Aramaic - See Ramban, who cites numerous examples of this.
Ramban: And "Dav'echa" is a Lashon of 'Da'avon' - sadness, which describes old age..
The Ramban cites the Targum Yerushalmi which also explains the Pasuk in this way. This explanations tallies with that of the Seforno - see answer #4 and note, only it uses different words.
Seforno: Like when you entered the land. This is similar to Rashi's first explanation - See answer #1 - only whereas Rashi explains the Pasuk with reference to the individual, the Seforno explains it in connetion with the whole of Yisrael.
