ויצא פרח ויצץ ציץ ויגמל שקדים (Bamidbar 17:23). It brought forth a blossom, sprouted a bud, and almonds ripened.
It says in Ben Ish Hai Derashoth that the reason that these three miracles happened to Aharon Hakkohen's staff -- it blossomed, sprouted a bud and bore fruit -- is because the Jewish people have three aspects to them, Kohanim (priests), Lewiim (Levites) and Yisraelim, which form an acronym in Hebrew of the word Keli (vessel).
If there is unity and a connection among the Jewish people then we have a complete vessel to receive the blessings from Heaven in, as it says, the only vessel that Haqqadosh Barukh Hu (the Holy One Blessed Be He) found fit for the purpose of receiving blessings for the Jewish people is Shalom (peace). Controversy and argument break the vessel into separate segments, and it will be unfit to hold the abundance and blessings.
Rabbenu the Hid"a, 'a"h, explains that a fruit tree has either the blossom or the fruit on it at any given time, but in this case they were both present together, and this was a miracle. The reason why there were almonds on it is because the people were diligent in the study of the Torah. The Hebrew word for almond (Shaqed) is similar to the word Shoqed which means showing diligence.
We see from this that unity amongst each other and diligence in Torah study bring much blessing to the Jewish people.
(See Parashath Qorah, Ben Ish Hai Derashoth. Hid"a, Homath Anakh)
