Jacob's Ladder

(12) עלים וירדים ASCENDING AND DESCENDING — It states first ascending and afterwards descending! Those angels who accompanied him in the land of Israel were not permitted to leave the Land: they ascended to Heaven and angels which were to minister outside the Land descended to accompany him (Genesis Rabbah 68).

(15) אנכי עמך I AM WITH THEE — God promised him this because he was in terror of Esau and Laban.

G-d showed him in a dream of prophecy that everything that is done in the world is done via the angels and everything is done through the decree of G-d, because the angels of G-d will not do any action until they return to G-d, and report to him what is going on in the world...And G-d was essentially showing him that He himself is standing at the top of the ladder, and he is promising Jacob that he will not be in the hands of the angels, but will be part and parcel of G-d, and G-d will be with him constantly...

According to Pirkei d' R'Eliezer this vision was like the covenant of the parts with Abraham, because the angels represent the four kingdoms - Greece, Persia, and G-d promised Jacob that G-d would be with them throughout the exiles at their hands, ,and he will guard and save them from their hands.

"God showed 4 kingdoms - their rise and fall - he showed them Babylon, Medes, Greece, and finally he showed them the kingdom of Rome which rose and didn't go down.

(14) והיה זרעך כעפר הארץ, ופרצת, after your descendants will have multiplied so that they are as the dust of the earth, numerically speaking, you will spread out. The expression is to be understood as similar to Isaiah 51,23: ותשימי כארץ גוך וכחוץ לעוברים, “so that you made your back like the ground, like a street for passers by.” Precisely when the Jewish people will have reached a seeming low point in their collective experience (downtrodden by the Egyptian taskmasters, or in later exiles) they will expand and become powerful in a measure never before seen on earth.

And he dreamed: The guide to the perplexed explains that G-d explained to Jacob the order of connection between the three worlds. The ladder on the ground refers to the ground on the lowest of the worlds, the head of the ladder refers to the middle world. The angels which were going up and down refers to the world of the angels. G-d standing at the top refers to the fact that G-d was higher than all the others, and rules everything.

The Abarbanel asks on the Guide:what is the purpose of this message to Jacob at this time and place?

I will answer the question:... Jacob was on the Mountain of Moriah on which the temple would be built. G-d therefore shows him the place where his children will build the temple, and these three worlds, because the temple has three levels which relate to the interconnectedness of these three worlds.

This is like the teaching of R. Jacob b. Iddi who asked: It is written, "Behold, I am with thee, and will keep thee whithersoever thou goest" (Gen. xxviii. 15), and then it is written, "Jacob was greatly afraid" (ibid, xxxii. 8)! But Jacob said, "Perhaps sin will cause [His protection to be withheld].