Why were the brothers jealous of Yosef?
Seforno: Because they attributed Yosef's newfound haughtiness to the rise in his father's esteem for him, which was why he dared say over the dream in his father's presence.
Ohr ha'Chayim: The latter dream could not be due to his thoughts. He would not think to rule over his father! Rather, it must be a prophecy. Ha'amek Davar - Also, it received such an interpretation (that even his father would bow to him).
Malbim: His brothers saw that there is reality to the dreams. They thought that Yaakov wants to crown him over them, and give the Bechorah and Berachah to him.
Gur Aryeh: Earlier, the brothers "hated him" (37:4,5,8); but now they were "jealous" of Yosef. Upon hearing the first dream, they had thought it was false. Once the dream was repeated, they realized it was true, and they were jealous. Refer to 37:10:2.2:1.
What does "v'Aviv Shamar Es ha'Davar" mean?
Rashi and Seforno: It means that Yaakov kept the matter in mind (waiting for it to materialize). 1
Because he sensed that the dream was true.
Why does the Torah see fit to record that Yaakov kept the thing in mind?
Rashbam: Because it explains why Yaakov retained his faith in the correct interpretation of Yosef's dream, so that, when he received the wagons, sent on the express orders of the King of Egypt, he immediately understood that the dream had come true. 1
Ha'amek Davar: It did not bother him (that he will bow to his son), for one does not envy his son.
Rashbam: In spite of the fact that he had seen Yosef's blood-soaked robe, implying that he had been killed. See Rashbam.
Why didn't Yaakov keep the first dream in mind?
Moshav Zekenim: Specifically the second dream had to be from Hashem - how else could Yosef have known that Yaakov is called 'Shemesh'? 1
Yosef did not tell the first dream to him - refer to 37:10:2.
When he lodged at Har ha'Moriyah on his way to Charan, he heard angels say "Ki Va ha'Shemesh" (28:11).
