Parashat Bemidbar: Halakhah

Halakhah הֲלָכָה

Given all the counting in our parashah, you might be surprised to learn that counting people is a complicated thing in halakhah!

When Benei Yisrael were counted in Shemot, the people gave coins so that the money could be counted instead of counting the people directly. The Torah explains why: וְלֹא־יִהְיֶה בָהֶם נֶגֶף (so that no plague would happen to them; Shemot 30:12).
The Gemara (Berakhot 62b) explains that King David made a mistake when he counted the people directly, and that caused a plague (Shmuel Bet 24). Yoma 22b says that it’s absolutely forbidden to count people, even for a mitzvah! The Gemara points to King Shaul as a positive example. He counted his soldiers indirectly; each soldier set aside a sheep, and Shaul counted those (Shmuel Alef 15:4).
Roundabout counting strategies
We see that sheep can work for counting and so can coins.
There are other strategies, too. When multiple כֹּהֲנִים (kohanim, priests) wanted to remove the ashes from the מִזְבֵּחַ (mizbei’ah, altar) in the Beit Ha-Mikdash, they’d stick out one or two fingers, and the person in charge would count the fingers, but not the kohanim directly (Mishnah Yoma 2:1).
While some halakhic authorities say this issue doesn’t apply anymore (Einayim Lemishpat on Berakhot 62b), most people think that counting people is still a problem. Better safe than sorry!
For a minyan
In Jewish life, the most common time we would want to count people is to see if there are ten for a minyan. Instead of using numbers to count who’s at shul, people often use a ten-word sentence, saying one word for each person present.
Some use this pasuk (Tehillim 28:9):
הוֹשִׁ֤יעָה ׀ אֶת־עַמֶּ֗ךָ וּבָרֵ֥ךְ אֶת־נַחֲלָתֶ֑ךָ וּֽרְעֵ֥ם וְ֝נַשְּׂאֵ֗ם עַד־הָעוֹלָֽם׃
Save Your people, bless Your inheritance, and carry them forever
Some use the blessing over bread, which is also ten words long:
בָּרוּךְ אַתָּה יהוה, אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם הַמּוֹצִיא לֶחֶם מִן הָאָרֶץ.
Blessed is God King Who brings bread from the earth

Or try making up your own ten-word phrase to use for (not) counting people!