"And he dreamed, and behold a ladder set up on the earth, and the top of it reached to heaven: and behold the angels of God ascending and descending on it. And, behold, the LORD stood above it..." - Genesis 28:12
Maimonides in his Guide for the Perplexed (1:13) discusses Jacob's dream, explaining the image of angels climbing a ladder as a description of the prophets attaining progressively higher levels of knowledge, ultimately reaching knowledge of God. The goal of attaining this knowledge is to 'govern and teach':
"For the angles of God are the prophets with reference to whom it is clearly said And He sent an angel (Num 20:16); And an angel of the Lord came up from Gilgal to Bochim (Judges 2:1). How well put is the phrase ascending and descending (Genesis 28:12) in which ascent comes before descent. For after the ascent and the attaining of certain rungs of the ladder that may be known comes the descent with whatever decree the prophet has been informed of - with a view to governing and teaching the people of the earth.