In the story of the blessings of Jacob and Esau, there are commentaries that ask, "What if Rebecca had not asked Jacob to pretend he was Esau."

The blessing that Isaac gave to Esau included the words, "V'haya asher tarid, u'farachta ulo me'al tzavarecha." "When you are aggrieved, you may cast off his yoke from upon your neck."

In this statement, Isaac was saying that there would be times when one brother would be elevated over the other brother. If Jacob had been in this position as Isaac had originally conceived, he would have attained an elevated status at a later time. As the story goes, Jacob had to flee immediately to avoid being killed by Esau. This helps us understand why Isaac was so fearful that things worked out the way they did.