What was unique about Avraham's camels?
Rashi: They were different than other camels, in that whenever they left Avraham's domain, they left muzzled, in order not to graze from other people's fields. 1
Ohr ha'Chayim: They were chice camels of Avraham thatq were to carry able to carry all the ?Kol Tuv Adonav? that Eliezer took with him to Charan.
Ha'amek Davar #1: They were tall and beautiful.
Ha'amek Davar #2: They muzzled themselves, 2 and would not eat from the property of others, like the donkey of R. Pinchas ben Ya'ir. 3
Refer to 24:10:152.
Other Mefarshim seem to assume that Eliezer had to put muzzles on them. Refer to 24:10:152.
See Chulin 7a.
Why did Eliezer need to take ten camels?
Hadar Zekenim: In order to transport the ten men - Talmidim of Avraham - whom he would later require when he betrothed Rivkah to Yitzchak, seeing as Birkas Eirusin requires a Minyan. 1
Ohr ha'Chayim #1: Considering the number of Avraham's camels, taking 10 was like taking one.
Ohr ha'Chayim #2: 'Ten' is not precise, like "Tov Lach, me'Asarah Banim" (Shmuel 1 1:8).
Malbim: It was in order to show Avraham's wealth, so the girl will want to come.
See Oznayim la'Torah there, who also proves that, (a) in the event that the family would not agree to the Shiduch, the men would testify to Avraham that Eliezer had done what he could to bring the Shiduch about, and (b) to prevent Eliezer from transgressing the laws of Yichud (being alone with Rivkah - though for these reasons, he would not have required ten men).
What are "all the good (things) of his master" to which the Pasuk is referring?
Rashi, Targum Yonasan and Ramban #1: It refers to a signed document 1 in which Avraham gave everything that he owned to Yitzchak, 2 as an incentive to allow their daughter to marry him.
Ramban #2: The Pasuk means to say that [Eliezer was able to take ten camels, because] all his master's assets [were under Eliezer's jurisdiction]. 3
Ramban #3: Ten camels laden with all the best of Avraham's household. 4
Seforno: Silver and golden vessels, and clothes. 5
Rashbam: Important men belonging to Avraham's household. 6
Hadar Zekenim: Ten men of Avraham's children (Talmidim), for Birkas Erusin.
Gur Aryeh: This must be the straightforward meaning of the Pasuk otherwise, what do these words come to teach us?
Presumably, this means that he would inherit it after his death - Refer to 25:5:1:2. See also Ramban.
As we learned earlier (in 24:2)
Like we find in Melachim II (8:9) and later in Bereishis 45:23.
To which the Torah refers later (in 24:54).
Where was Aram Naharayim?
Rashi: Aram Naharayim was situated between two rivers - the Peras and the Chidekel. 1
It was the country (in which Charan was situated and) from which Avraham stemmed (Berachos 13a).
Why does it add "va'Yelech" in between "va'Yikach" and "v'Chol Tuv Adono b'Yado"?
Seforno: What the Pasuk means is that before leaving with his master's camels, he obtained permission from him to do so.
Ha'amek Davar: Even though Avraham's camels were working in the field, and it would have been easier to borrow or buy camels from others, Eliezer specifically gathered them 1 and took them to Avraham's house to load them.
Having just stated that Eliezer departed, why does it repeat "va'Yakom va'Yelech"?
Oznayim la'Torah: Perhaps it is to hint that Eliezer had 'Kefitzas ha'Derech' 1 - that the moment he arose to leave Chevron, he arrived in Aram Naharayim (alias Charan).
Ha'amek Davar: The first "va'Yelech" refers to gathering the camels (refer to 24:10:4:2); here it refers to going to Charan.
QUESTIONS ON RASHI
Rashi writes: "Avraham wrote a document gifting of all his possessions to Yitzchak." But what about Yishmael? One may not transfer inheritance, even from a bad son to a good son (Kesuvos 53a)!
Refer to 25:5:151:1; refer to 25:5:151:2.
Rashi writes: "'From his master's camels' - ... They would go out muzzled [to prevent] theft, so they would not graze in others' fields." Why was this necessary? Were they inferior to the donkey of R. Pinchas ben Ya'ir, which refused to eat untithed food (Chulin 7a)?!
Bartenura: R. Pinchas ben Ya'ir's donkey refrained by itself, for it was special for the Tzadik to ride on. The camels were for loads. Perhaps the animal that Avraham rode on would refrain from Isur, like R. Pinchas' donkey.
Mizrachi: When the damage is established (it will pass through others' fields), we do not rely on miracles, 1 just like we do not rely on a Mitzvah to protect from a known danger.
Sifsei Chachamim: What borders Reshus ha'Rabim is Hefker, for the owners despair of using it. Eliezer was a Chasid and did not want to benefit from others, even with a Heter.
Oznayim la'Torah #1: This was necessary to teach people to do likewise.
Oznayim la'Torah #2: Not to do so would have smacked of conceit (by acknowledging that he was a Tzadik to whom miracles occurred).
Oznayim la'Torah #3: Avraham was too modest to assume that his camels would refrain from eating other people's crops.
Gur Aryeh answers similarly - It is forbidden to rely upon miracles. (In the story of the donkey of R. Pinchas ben Ya'ir, he had arrived with the donkey at an inn, and was no longer in the fields, and as such he may have removed its muzzle. Also see a similar story in Shekalim 13b.) (CS)