"I've done everything I can to bring Moshiach," he said. "I now hand over the task to you. Do everything you can to bring him!"
This unusual communique threw chassidim into a state of frenzy. "What did the Rebbe want us to do, especially if he himself could not bring about Moshiach's arrival?" they said. "What does he expect of us to do now?" many questioned.
Many groups formed, each hastily gathered in ad hoc meetings with friends or associates, to try, calmly and reasonably, decide on an effective course of action. "How did the Rebbe want us to pursue bringing Moshiach," was the main topic. Urgency filled the air. Some were at their wit's end. Everybody hankered to know what his friend thought. None really knew what the Rebbe suggested, but they knew for sure it was an outright call to take action.
Of several initiatives, one in particular bore fruit. A chassid by the name of Nachshon appeared to be its prime architect. Let a rabbinic court convene to formulate and endorse a decree that ratifies the Rebbe as King Moshiach! This was, in fact, soon done and many rabbis of Chabad from the U.S. and around the world signed the decree.
Four days after that talk, on Monday, 2 Iyar, Nachshon handed the rabbinic court's signed decree to the Rebbe. The Rebbe accepted the document with a big smile and said to Nachshon,
One month later, some rabbis suggested the need to read the rabbinic decree at the gravesites of the previous Rebbeim and of the Rebbe's father, in the Soviet Union, to request of these spiritual giants to effectuate the revelation required (i.e., that this decree serve as impetus to launch Moshiach and render the Redemption). They chose Nachshon and his friend Avi to undertake the mission.
The week this pair returned from their trip, the Rebbe spoke on Shabbos (portion of Shelach) of the two spies Joshua silently sent to spy in the Land of Israel (without the fanfare raised as with the spies sent by Moses), and how this mission in particular, as opposed to the spy mission discharged by Moses, succeeded and served its purpose. A casual reader of the long talk that Shabbos might think it was just another talk like many, with a subject chosen from the portion at random. By not knowing the events of the prior 8 weeks, particularly the past two weeks, he would have lost the added significance attributed to "the two silent spies".
[A more recent psak din can be downloaded here.]