The Zohar tells us that Jacob is beginning a very difficult spiritual journey, which involves conjoining the two worlds of Zeir Anpin and Malchut. Here, Jacob is coming full circle - completing his journey and thereby unifying Zeir Anpin and Malchut.
Passion and enthusiasm for spiritual wisdom and growth are easily aroused when one begins to walk the spiritual path. However, when the inevitable obstacles surface to test our commitment and shed light on our negative qualities, so that we can confront them and remove them from our nature, we lose the fire and most of us fail to complete the journey. It is much easier to start a new search elsewhere and feel new passion again, than it is to confront the dark side of our nature and complete our journey. Constant seeking, however, will not conjoin the two spiritual worlds; thus it delivers short-lived passion, and fails to provide long term fulfillment. The Evil Inclination will always stand by us and help rationalize and justify our quitting and giving up. In response, the Zohar verses herein give us the energy and willpower to complete our path and finish what we have begun, so that we can achieve true and eternal contentment.