Midrasch zu Jirmejahu 13:18

...And he dreamed and behold there was a ladder -- Rabbi Abuhu said: The words of dreams do not ascend and do not descend. Once a man went before Rabbi Yossi bar Halafta. He said: I saw in my dream, they said to me, "?????" He [Rabbi Yossi] said: "????". He said to him: "No! He said to him: "..." He said to him: "I don't have 20!" He said to him: "And if you don't have 20, count from their heads to their tails, and from...".... Bar Kapra taught: There is no dream that does not have an interpretation. Behold a ladder, this is a sheep. Placed on the earth, that is the altar (Exodus 20), Make me an altar of earth. And it's head reaches the heavens, those are the offerings, whose scent rises to the heavens. And behold the angels of God, those are the high priests. Rising and descending on it, that rise and descend with a sheep. And behold God is standing on it, (Amos 9): I have seen God standing on the altar. The rabbis interpret it as Sinai: He dreamed and behold there was a ladder, that is Sinai. Resting on the ground, (Exodus 19) and they stood at the bottom of the mountain. And its head reached the heavens, (Deuteronomy 4) And the mountain burned with fire unto the heart of heavens.....