Why does the Torah use the double expression "va'Yira Me'od... va'Yetzer Lo" (He was afraid and he was distressed)?
Rashi: He was (very) afraid that Esav may kill him, and distressed that he may have to kill Acherim (others, i.e. Esav, 1 in self-defense).
Ohr ha'Chayim: He was afraid not to arm himself, in case Esav comes for war. He was distressed, for perhaps Esav truly felt brotherhood, but when he sees that Yakov armed himself, he will say that Yakov seeks his evil, and this will arouse his hatred!
Hadar Zekenim, Da'as Zekenim: Yakov was pained that he was afraid in spite of Hashem's promise. Malbim - this showed that his trust in Hashem was not absolute, therefore he was not worthy of miracles. This distressed him, and he was forced to make natural preparations for war. Ha'Emek Davar #1
See also Sifsei Chachamim. Why should he be distressed about killing Esav? One should kill one who seeks to kill him! V'Lo Od Ela (Perek 44) - Yakov knew (through Ru'ach ha'Kodesh) that R. Meir, who is called Acherim, should descend from a convert from Esav. He feared lest he kill Esav, and effectively kill R. Meir. This is why after Yisrael entered Eretz Yisrael, they 'forgot' about wiping out Amalek until Hashem commanded them. (This is difficult. We cannot uproot our Mitzvah due to such concerns! Further, R. Meir could come from a part of Esav's family other than Amalek! And even if he must come from Amalek, (if we do not accept converts from them, from a female Amalekis who married a different nation), perhaps R. Meir's Amaleki ancestor already converted or had children from another nation, so wiping out all current Amalekim will not affect R. Meir! And why was Yakov worried? If he needs to kill Esav, presumably, R. Meir will come from a child of Esav who was already born (Esav was 97 years old, and he married his last wife 34 years ago)! Perhaps Ru'ach ha'Kodesh told him that R. Meir will come from a child of Esav who was not yet born. Rashi (Shemos 2:12) says that before Moshe killed the Mitzri, he saw that in the future, no one [destined to come] from him will convert.
What led Yakov to believe that Esav's visit was not a friendly one?
Ramban #1: The fact that Esav (unexpectedly) 1 left his home-town to come and meet him, and that he was coming with 400 men was a clear indication that his visit was anything but friendly.
Ramban #2: In fact, Esav declined to receive Yakov's messengers, 2 because his fury (against Yakov) never abated. 3 And when the messengers inquired in Esav's camp, they discovered that Esav was on his way with an army 4 - which they duly passed on to Yakov (in Pasuk 7). 5
What caused Esav to change his mind?
Ramban: He changed his mind at the last minute - when he saw the great Kavod his brother showed him, and when he saw him bowing down to him seven times and humbling himself before him, his heart melted, because he thought that Yakov was conceding that he (Esav) was the Bechor. 1
Bearing in mind Hashem's promise that his offspring would increase like the dust of the earth, why was Yakov afraid?
Rashi (Pasuk 11) and Ramban (Pasuk 13): He was afraid that, since Hashem's promise, his merits had diminished on account of his sins, and that he was no longer worthy of Hashem's protection. 1
Rosh, Hadar Zekenim (9), Da'as Zekenim (12): Hashem promised me when I was alone - "Ki b'Makli..." Now I am two camps. Perhaps Esav will strike my family, "Em Al ha'Banim"! 2
Hadar Zekenim #1, Da'as Zekenim #1 (from Bereishis Rabah 76:2): Yakov had neglected Kivud Av v'Em for 20 years [and he was later punished for this] and Yishuv Eretz Yisrael, and Esav had these merits. 3
Hadar Zekenim #2, Da'as Zekenim #2: Esav had said that he will kill Yakov after his father dies. Yakov feared that this had occurred. 4
Hadar Zekenim #3, Da'as Zekenim #3, Malbim: Indeed, Yakov was pained that he was afraid in spite of Hashem's promise.
Oznayim la'Torah: The question is even more blatant, bearing in mind that Yakov was that much stronger than Esav, 5 and could easily have killed him if attacked. The trouble was that, based on Yakov's words and actions, it is clear that he did not know whether Esav was coming to kill him or to greet him in peace
Ramban Tzadikim are constantly afraid of having sinned, which is why Yakov was afraid that he had sinned even after having left Charan, for having made a covenant with Lavan ha'Rasha or in some other way.
Ba'al ha'Turim: Esav might kill my children, and Hashem's promise would be fulfilled with children that I will bear later (Refer to 32:12:2:1). This is similar to the explanation of the Ibn Ezra (in Pasuk 9), which the Ramban rejects.
Rav C.P. Scheinberg - Yakov was worried, lest it was harder for Esav to guard these two Mitzvos than for Yakov to guard 613, so Esav has greater reward.
This explains why Yakov said "Elokei Avi Yitzchak" (even though before he did not, for we do not put Hashem's name on a living person - refer to 31:42:1:1).
Oznayim la'Torah: His enormous strength is highlighted by his ability to roll the stone off the well
Which two camps did Yakov plan to make?
Targum Yonasan: He divided his entire camp into two sections, one of Leah 1 and one of Rachel.
Ohr ha'Chayim: The first camp showed brotherly love, and the other was ready and armed [for war, since Yakov was unsure of Esav's intent].
Malbim: One was of his wives and children, and one was his flocks and shepherds.
Why does the verse not mention dividing the children?
Ha'Emek Davar: He guarded the children with himself. Hashem had promised him that he and his seed would not be wiped out. Also, he could not be killed until Binyamin (i.e. his 12th son) was born and grew up. 1 This is the source that no Shevet can be wiped out. Rather, he was worried about his property, slaves and [his Tefilah
Granted, his wives knew through Ru'ach ha'Kodesh that he will have 12 sons. What is the source that Yakov would raise all of them? Perhaps one of his wives was pregnant! Must we say that all of them were Nidah, and surely not pregnant?? (PF)