Parshas Va'era commences with a series of exchanges between Hashem and Moshe, in which Moshe expresses his reluctance to return to Pharaoh and call for the liberation of B'nei Yisroel. Why Did Moshe continue to decline this assignment, such that we read again and again of Hashem instructing him to go to Pharaoh, with Moshe each time seeking to be dismissed from the task?    

The answer to this question may be deduced from the end of Parshas Shemos, in which Moshe is rebuffed by Pharaoh and then returns to Hashem in despair, asking why he was sent on such a failed mission. Hashem replies that Pharaoh will indeed send out B'nei Yisroel, and He provides Moshe with much encouragement and more details of His plan for the people's salvation.

One may suggest that Moshe had to undergo this period of dire frustration in order to internalize the emotional plight of B'nei Yisroel. As was explained in a d'var Torah in this series on last week's parshah, Moshe Rabbeinu needed to identify with his task on a very personal level. In this vein, it was required that Moshe experience within himself the frustration and despair of B'nei Yisroel, who appeared to be in a hopeless position. Their slavery had already endured for over 100 years, and the promises of Yaakov and Yosef that Hashem would redeem the nation seemed so distant and bleak. Although the Jews still believed in the ancient pledge that they would be freed and return to their homeland, the realization of this did not seem to be coming anytime in the foreseeable future. It was therefore necessary for Moshe, in a similar fashion, to feel that he was up against a brick wall and sense that Pharaoh was unyielding to Hashem's charge, that B'nei Yisroel were no longer interested in his message, and that Moshe himself was not even equipped to deliver the message properly. Moshe had to experience the same comprehensive desperation as the people he was about to lead in order to internalize their emotions. Only then would Hashem enable Moshe to succeed.

Thus, Parshas Va'era presents the repeated back-and-forth of Hashem's assignment to Moshe and Moshe's decline of such as a continuation of Moshe's display of despair at the conclusion of Parshas Shemos. The repeated charges to Moshe Rabbeinu to fulfill Hashem's mission for B'nei Yisroel were necessitated by Moshe's mounting internal feelings of hopelessness about the situation in terms of Pharaoh's lack of receptiveness, B'nei Yisroel's lack of receptiveness, and Moshe's own lack of ability. It was specifically the internalization of this all-encompassing sense of hopelessness which qualified Moshe to lead, for he now most personally identified and was invested with the people's profound anguish.

Parshas Va'era thus marks the completion of Moshe's assignment from Hashem and investiture as the redeemer, for the comprehensive despair he experienced on a personal level merged him with the people and qualified him to lead them toward the Redemption.