Korach - Vigilant in Mitzvot

Speak to the children of Israel and take from them a staff for each father's house from all the chieftains according to their fathers' houses; [a total of] twelve staffs, and inscribe each man's name on his staff.

דַּבֵּר | אֶל בְּנֵי יִשְׂרָאֵל וְקַח מֵאִתָּם מַטֶּה מַטֶּה לְבֵית אָב מֵאֵת כָּל נְשִׂיאֵהֶם לְבֵית אֲבֹתָם שְׁנֵים עָשָׂר מַטּוֹת אִישׁ אֶת שְׁמוֹ תִּכְתֹּב עַל מַטֵּהוּ

Bamidbar 17:17

 Asks the Noam Elimelech, why do they have to bring 12 staffs, for in the end the miracle that reaffirmed Moshe's authority occurred only to the staff of Aharon? And if you were to say that the other tribes would suspect that perhaps there staff could have been endowed with the same miraculous qualities as Aharon's staff, then they could have independently brought their staff to the ohel moed, and not brought them all together. Why bring 12 staffs and all at one time?

Vigilant Watching
The Noam Elimelech addresses this question by bringing a verse from Mishle.

Fortunate is the man who listens to me to watch by my doors day by day, to watch the doorposts of my entrances.

אַשְׁרֵי אָדָם שֹׁמֵעַ לִי לִשְׁקֹד עַל דַּלְתֹתַי יוֹם יוֹם לִשְׁמֹר מְזוּזֹת פְּתָחָי

Mishle 8:34

The verse could have written "דלתי" (doors) to refer to openings in the plural. However one needs to attach oneself and serve Hashem with all his traits. That one shouldn't say to himself its enough to choose which trait to invest oneself in - like to just focus on learning, or just on prayer, or just on charity. One needs to invest oneself with all one's soul in all the traits possible and likewise all mitzvot.

That is why this verse uses the word "דלותתי" to show that one should be vigilant at ALL the 'doors', for if the phrase had just used "דלתי" then one could assume that the simplest meaning of plural would be sufficient. Thus the verse includes the plural version that includes the widest array of possibilities.

12 Staffs at Once
The essential collection of traits come to mirror the traits of the 12 tribes. For every tribe had a trait that it was strongly identified with. Likewise, we need to embrace all of these traits to serve Hashem.

Thus Hashem commanded that 12 staffs be brought at one time to the Ohel Moed, in order to suggest that the we are obligated to take on all these traits and be vigilant in them.

Almond Blossom
This addresses Rashi's observation as to why the staff of Aharon produced almond blossoms.

ויגמל שקדים when the fruit was recognizable, it was recognized that they were almonds...Now why [did it bear particularly] almonds?

Rashi's commentary on Bamidbar 17:23

Am Yisrael didn't understand why they were commanded to bring all 12 staffs at once. Only when they saw that Aharon's staff blossomed almonds (שקדים) did they realize the message and the great miracle - that is that need to be vigilant (שוקד) for all good traits. This includes all the traits signified in the tribes. This connects to the meaning of watching by the doors every day (לִשְׁקֹד עַל דַּלְתֹתַי יוֹם יוֹם).

We should strive to infuse in our lives the spectrum of mitzvot.