It’s strange that Rivka never tells Yitzhak that she was told by God that Yaakov was to become the greater son, even though it probably would have made her life a lot easier.
There seems to be a general pattern among the avot/imahot (patriarchs/matriarchs) that prophecies they receive are kept secret and shared with others only on a “need-to-know” basis.
Avraham presumably didn’t tell Sarah of God’s promise that they will have a son, even though this was what they’ve been waiting for their whole married life. He told his household about circumcision, which was announced by God during the same prophetic episode, but not a word about the new son. Sarah only found out when God announced it a second time through the three angels that came to visit them afterwards. Avraham didn’t tell Sarah about the Akeidah (and he only gave the slimmest hint to Yitzhak). It’s also not at all clear if Avraham ever shared with anyone what he learned of his family’s future during the brit bein habetarim, in which God told him that his descendants will be exiled for 400 years before returning to the land of Canaan. It was either not shared at all, or it was a closely guarded secret known only to the family’s top leadership (Isaac and then Jacob?) because otherwise, Jacob’s entire family would not have willingly gone down to Egypt.
The one exception is Yosef, who freely announces to this entire family his prophetic vision of bowing sheaves and stars, and it’s striking that he was castigated by his father for doing so. Perhaps the young upstart was throwing aside what “everyone knew”, that you keep your prophetic visions to yourself unless otherwise instructed or until it’s directly and immediately relevant.
Akedat Yitzhak Takes 