The events leading to Yitzchak's 'mistaken-identity' blessing of Jacob are discussed by Rabbi Elazar, as he expounds upon the significance of trust in the story of the fiery furnace. In the story, three righteous people are tossed into a fire. The men possess unshakable trust in the Creator, and have no regard for their survival or destruction. For this reason, these righteous men miraculously avoid injury.
Through this story, Rabbi Elazar shows, in great depth, that only complete trust in the Light of the Creatort can bring forth Divine assistance. There must be no expectation or desire for a specific result - as is written, "according to his need." We're told of the importance of being prepared, and of dwelling on the Name of the Creator, and of how these qualities are intricately related to Torah study. Such study, we learn, requires a profound intention to extol the Creatort. Our efforts must be for the sake of the whole world, not for ourselves, so the earth shall be full of the Knowledge of the Creator. The Rabbis then return to the story of the blessing, its significance for future generations, and its relation to both the Shechinah and this mundane realm of Malchut.
People may unknowingly embark on a spiritual path for selfish reasons. They have hidden expectations of self-serving gain. Though this is not always their conscious intention, it is the reality. We can know if our desires and efforts are pure when we ask the Light for what we need and not just what we want. We then trust in the spiritual path, regardless of any tests and obstacles we encounter. These verses increase our level of trust in the Creator. They invoke certainty in times of distress, strength during times of strife. We can embrace whatever life brings, certain of the spiritual purpose behind it.