One of the main methods of Yaakov’s service of Hashem was in combining opposites. His attribute of Tiferes was about merging the good qualities of different and opposite aspects, like kindness and severity.
Through combining opposite aspects in holiness, he reveals the Infinite Light of Hashem, the truth of Hashem how He contains all opposites in Himself as one.
Tohu and Tikkun are also opposite modes of holiness. Tohu functions in an encompassing manner. It gives unlimited energy and passion in each Sefira, an energy that cannot be contained and encompasses the recipient. Tikkun functions in an internalizing manner. All the Light and energy is channeled into the parameters of the recipient so that it can be fully internalized and integrated into the all the aspects of the recipient.
Through combining these two opposite modes of holiness, Yaakov would reveal the Infinite truth of Hashem, how Hashem is both Encompassing and Internalizing and beyond both modes at the same time.
This is why he wanted to receive the Encompassing Lights of Tohu from Eisav: So that by merging it with his Internalizning Lights of Tikkun, he can reveal the Infinite Light of Hashem includes and transcends both modes.
