"AND JOSEPH DREAMED..." (Beraishis 37:6)
In the ensuing narrative, it is noteworthy that dreams are conspicuous. Joseph dreamed two dreams, the Master of the Drink and the Master of the Bakers both dreamed, and Pharaoh dreamed twice. These six dreams were of the greatest consequence...
Joseph’s dreams 1) served the purpose of augmenting his brothers’ envy and causing them to sell him; 2) and they caused the brothers subsequently to perceive that Joseph was chosen by Hashem to rule over them, and they were therefore more ready to defer to his authority in Egypt.
The dreams of the Master of the Drink and the Master of the Bakers were necessary in order to cause Joseph to be known as a true interpreter of dreams. Pharaoh’s dreams caused Joseph to become the second in authority in the land, and thereby he was enabled to rule his family and the ensuing nation so that he prepared them to endure the Egyptian bondage and to be worthy of receiving the Torah. The Torah is not emphasizing the importance of dreams. Only these dreams were significant, because Hashem sent them for the sake of His chosen people.
The dreams caused the brothers to perceive that Joseph was chosen by Hashem to rule over them
The conspicuous number of dreams in the history of Joseph was due to his excellence. These dreams were sent by Hashem either directly to Joseph, or were sent to others because of Joseph. When the officers of Pharaoh dreamed, and when Pharaoh dreamed, they did not deserve the honor of a message from G-d, but just as Bileam’s donkey spoke because of Hashem’s prophecy to Bileam, so also did the Egyptians dream because of Hashem’s messages for Joseph’s sake. But these dreams demonstrate that the excellence of Joeph was inferior to that of Jacob and Jacob’s fathers. The three Fathers were prophets, but their children were not prophets.
The dreams of Joseph were minor forms of Hashem’s communication with him, but even Joseph was unequal to his father’s greatness. Never is it stated that G-d spoke to Joseph, or that an angel appeared to him; and he was not interred in the Cave of Machpelah.
(The fact that angels appeared in later generations and that prophecy was granted to them, is due to the system instituted in the days of Moshe; which continued down to the end of the First Sanctuary. Moshe was given the power of open and immediate miracles. The prophets that followed were Moshe’s disciples, and they too performed open miracles and saw angels. But before Moshe, prophecy was not a tradition and was therefore achieved only by the very greatest.) — The Beginning