Ascending and Descending

Rashi: ascending and descending: Ascending first and afterwards descending. The angels who escorted him in the [Holy] Land do not go outside the Land, and they ascended to heaven, and the angels of outside the Holy Land descended to escort him.

Baal HaTurim: "a dream" spelled in full has gematria of 84, equal to that of Zehu Binvuah meaning 'This is through prophecy'.

Nefesh HaChayim (translation by R. Finkel, 2009): Even within man himself, the 3 elements of Nefesh [the animalistic element of the soul], Ruach [the element above Nefesh], and Neshama [the most lofty component] attain the power to elevate themselves and the higher worlds only when they descend to this material world and enter the physical body of man. For it says, "Then the L-rd G‑d formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul". (Gen. 2:7)

First G‑d breathed, and only then man became a living being. The descent of the soul in this world is exemplified by the ladder of Yaakov's dream. (See Zohar Naso 123.) "And he dreamed, and behold! a ladder set up on the ground." The ladder clearly represents the soul of life. And, "angels of God were ascending and descending upon it" signifying that by standing on the ground, the soul's lower end becomes "clothed" in the garment of man's body. (Ibid. Chapter 10)

Targum Yonatan [28:10]: 'Five miracles occurred with Jacob when he left Be'er-Sheva:
1.The day was cut short, and the sun set before its time, because G‑d wished to talk to him
2.When he awoke in the morning, he found that the four stones (depicting the four wives that he was destined to marry) that he had placed under his head when he lay down, had turned into one stone
3.He rolled the stone from the well - with one hand, although normally, it required the combined effort of all the local shepherds to remove it
4.The well began to flow and the water rose to meet him, and it continued to flow for the entire duration of Jacob's stay in Haran (in verse 10, the Targum will add that it flowed for twenty years)
5.The earth 'jumped' before him, and on the same day that he left home he arrived in Haran.

Ramban: In a prophetic dream, G‑d showed Jacob that whatever is down on earth is effected by means of the angels, and that everything is done by decree given to them by the Supreme One. "For He will give His angels charge over you, to keep thee in all your ways". (Psalms 91:11).
This vision was like that given to Avram at the time of the covenant "between the parts" for He showed Jacob the dominion of the 4 Kingdoms of Greece, Persia, Babylon, and Edom

Ohr HaChayim:: "He dreamed that there was a ladder." Since many dreams contain matter without import, the Torah added the word "And behold!" [in Hebrew, "v'henai"] to indicate that in this dream every detail appeared to Jacob as especially vivid and important. He had total recall of everything he dreamed, and referred to each detail later on. This is why the word "Behold" is repeated before every segment of the dream. The Torah thereby characterizes the dream as a prophetic revelation.

Maggid Mesharim: "The ladder was set earthward and its top reached to the Heavens." The ladder was the illuminating sefirot that give light to Kenesset Yisrael — malchut below that is called earth. Its top reached toward the Heavens — that by means of the illuminating sefirot in malchut, malchut below can connect itself to the top of the Sefirot to the upper 3 Sefirot that are called the Heavens, in the plural. "And behold angels of G‑d were going up and down on it ['bo', spelled beit-hei]" That is they were ascending to bina [the eighth sefira counting from the bottom, starting with malchut] for the gematria equivalent of the word 'bo' is 8. Besides, the beit hints to bina as it is the first letter of both bo and bina. It is also stated that by the letter beit attaching itself to the vav, [the two letters of 'bo'] the Sefirot ascend toward bina.

Lubavitcher Rebbe: Rashi said that the angels which escorted Jacob in the Land of Israel were not permitted to leave the Land, so they ascended to Heaven, and the angels of Exile descended from Heaven to escort him further. The Land of Israel was not holy in the times of the Patriarchs, which is why they left the Land on a number of occasions. But if it was not yet holy, why were angels forbidden to leave?
...in heaven, the Land of Israel is always associated with holiness.
Although the physical land had not become holy, in heaven the Land has always been desired by G‑d. Jacob and his descendents who lived down here on earth were allowed to leave the Land, since the physical Land had not become holy yet. But angels who dwell in Heaven were not permitted to leave since in heaven, the Land of Israel is always associated with holiness. (Likutei Sichot 25:152)

Zohar Vayetze 149: Come and see: "And he dreamed." How could it be that to holy Jacob, the chosen of the patriarchs, and in such a sacred place, G‑d was revealed only in a dream?
Jacob was not yet married and Isaac was still alive. You may wonder why, after he was married, it is written: "I...saw in a dream". (Gen. 31:10) This was because he was outside Israel, and Isaac was yet alive. Therefore it is written that he dreamed.
Afterwards, when he came to the Holy Land with the tribes and "the barren woman" was perfected with them: "and be a joyful mother of children". (Psalms 113:9) It is written: "And G‑d appeared to Jacob," (Gen. 35:9) "And G‑d spoke to Israel in the vision of the night". (Gen. 46:2)