After the failed rebellion there were those who were still not convinced that Aharon was entitled to the priesthood, so Hashem created a test. A leader from each tribe handed in a staff, and from whoever’s staff blossomed flowers had the Divine right to the priesthood. Of course only Aharon’s staff did so .
From the third possibility we learn a very telling lesson on how to diffuse an argument, the medrish relates::“There are those who say that Moshe took one beam and split it into 12 planks. He told them that your staff came from one source. Why did he do this? ‘It is honor for man to refrain from quarreling, and every fool will be exposed’ (Mishlay 20:3). So that they will not say [Aharon’s] staff was wet and therefore it blossomed. Hashem made a decree on [Aharon’s] staff and Hashem’s Explicit Name was found on its buds as it says “It gave forth blossoms, sprouted buds and produced ripe almonds” (Bamidbar 17:23). It produced fruit for all those who take good care of the Tribe of Levi. Why almonds, why not pomegranates, or tree nuts? Because Jews are compared to those others” (Medrish Rabba on Bamidbar 18:23).
The Mahar”zu, a commentary on the Medrish Rabba says: “Hashem performed this miracle of the staff so that the Jews won’t argue with Moshe anymore. Even though Hashem could have taken care of matters differently, for example, anyone who starts a fight will be punished just as Korach was, He still didn’t do that. From here we should all learn not to sustain strife.” The Mahar”zu next points out, “When taking a staff from a wet tree it might be able to blossom after a while but it cannot sprout buds and produce almonds nevertheless they might have had a slight excuse so in order to remove any excuse, all the staffs came from one beam, making them all equal.” Lastly, the Mahar”zu quotes different pesukim which equates the Jewish people to pomegranates and tree nuts and then adds, “And since these are to praise and glorify them it would be unbefitting for them to be used for something unpraiseworthy like here.” That is why almonds were used. (Click here for Hebrew text)
It would seem that taking these three elements into account is a working formula to avoid maintaining strife.