Seeing (or is it counting?) double
שאו את-ראש כל-עדת בני-ישראל למשפחתם לבית אבתם במספר שמות כל-זכר לגלגלתם: פקד את-בני לוי לבית אבתם למפחתם כל-זכר מבן-חדש ומעלה תפקדם
Count the heads of the entire assembly of the Children of Israel, by their families and their father’s houses, by the number of the names, all the males, by their heads. Count the Levites according to their father’s houses and by their families. Count all the males from one month of age
Sefer Bamidbar’s English name of Numbers is aptly put, as there are many censuses that are described throughout the book. This parsha alone contains two censuses, one of the Jewish people at large (excluding the tribe of Levi), and one exclusively of the tribe of Levi. The two censuses have some differences. One of them is the main census of the people was of all the males above the age of twenty. This is not like the census of the tribe of Levi, which counted all males from the age of one month and up. Another difference is regarding the general census of the people, the Torah stresses that they be counted by their heads. This requirement is strangely absent from the census of the Levites. Regarding this latter difference, why did the Torah leave out the requirement of counting by their heads?
The Chasam Sofer cites a fascinating, albeit seemingly supernatural explanation. The Torah is avoiding a problem. If there would be a requirement to count the heads of the Levites, like there is with the other tribes, the count could end up being inaccurate. If there were to be a Jew with two heads, they would end up being counted as two people, when in fact they are one. As such, the Torah left out the requirement of counting the Levites by their heads. However, there was no problem mentioning counting the rest of the Jews by their heads. Their census started from the age of twenty, and there’s no way that a person with two heads would live so long. The problem was only with the Levites, whose census counted those as young as a month old.
While this explanation seems to cleverly resolve the inconsistency, there are those who question its premise. Chazal tell us that if there would be a case of a firstborn male born with two heads, he would have to give double the requisite amount to perform pidyon haben. The reason is because the Torah cares about the number of heads to determine how much money is needed to redeem such a firstborn. It would seem to be then that the Torah considers such a being to be two people, not one. If so, what’s the problem that the census would count such a person twice? Furthermore, the whole purpose of the census of the Levites was to have them take over the holy status of the firstborn of the other tribes. If pidyon haben is determined by the number of heads, it would make sense the Levite’s replacement of the firstborns would also be determined by the number of heads. It must be then that there was no concern for a two-headed person in the generation that left Egypt. They were all born wholesome and healthy.
As a result, they offer a different suggestion for the inconsistency. As a result of the difference in ages for the census, where the general census was from twenty and up, and the Levites were counted from one month and up, there was another difference: the method in which the census was conducted. The general census involved simply counting the Jews one by one. However, Moshe was concerned how he could count how any infant babies there were. He felt it was a breach of modesty to enter the tents of all the Jews, where the mothers could be nursing their young babies, in order to conduct this census. Hashem informed him that if he were to simply walk to each family’s tent, a Heavenly voice would announce to him how many babies were to be found. What comes out from this is that Moshe didn’t actually individually count all the Levites. He was aided by the Hashem’s Heavenly voice. The Torah therefore couldn’t command to count the Levites by their heads, as Moshe wasn’t going to count their heads anyways.
 Based on Teshuvos Chasam Sofer Yoreh Deah § 294 s.v. וראיתי and Binyan Shlomo Chiddushim Al HaTorah to Numbers 3:15
 See Penei Dovid ad. loc. for an attempt at explaining the meaning of this phrase
 Numbers 1:2, 3:15
 The English name (really Greek), like all the five books of Moshe, is really just a translation of the name Chazal gave the sefer: ספר הפיקודים (for example, see Sotah 41a)
 Loc. cit., in the name of Rav Shmuel Krakwar, in his sefer Kol Yehuda. Regarding this explanation, the Chasam Sofer writes ודפח”ח, which is used to denote approval of a clever suggestion
 See Menachos 37a. While this discussion may sound like science fiction, if we interpret a two-headed person to be a set of Siamese twins, it makes perfect sense. Even in our days there’s a case of Siamese twins who have one body, with one set of arms and legs, yet have two heads. Each head controls their side of the body (see https://en.wikipedia.org/wiki/Abby_and_Brittany_Hensel). For a fascinating treatise on the halachic implications of Siamese twins, see Rabbi Reuven Chaim Klein’s excellent article, Til Death Do Us Part: The Halachic Prospects of Marriage for Conjoined (Siamese) Twins, Hakirah XXVI (viewable at http://hakirah.org/Vol26Klein.pdf)
 The language of the Chasam Sofer is לא יחיה כל כך זמן רב. The Binyan Shlomo loc. cit. assumes he meant that a two headed person wouldn’t live more than twelve months. However, the Chasam Sofer says this explanation doesn’t fit with the opinion of the Rashba (Teshuvos HaRashba § 98), that a being with an extra limb (in this case, a head) will in fact live a full life, and can even procreate. He also brings from the Maharshal in his Yam Shel Shlomo Chullin 3:80 that even a definite טריפה, which we say won’t live more than twelve months, sometimes can live. See also Shach to Shulchan Aruch Yoreh Deah 57:18 § 48, the Rashash’s son, Rav Matisyahu Strashun’s Mises Yah to Shemos Rabbah 2:6, and Penei Dovid to Numbers 3:15. Some of these sources came from Rabbi Klein’s above cited article. See there, fn. 5 for more sources
 Rav Shlomo HaKohen of Vilna, also known as the Cheishek Shlomo, the editor of the Vilna Shas, in his Binyan Shlomo loc. cit.
 Menachos loc. cit.
 Numbers 3:47. Going back to the census of the eleven other tribes, the Chasam Sofer brings from the Rema MiPano in his Asarah Ma’amaros Eim Kol Chai 1:3 that the reason why the Torah said to count by the number of heads was because Moshe saw all the generations that will come from each Jew. Meaning, their reincarnations, as גולגולת is related to גלגול (Yoel Moshe ad. loc., explaining the intent of the Asarah Ma’amaros). See also Yalkut Reuveni ad. loc. However, the Binyan Shlomo is bothered that this understanding of גולגולת isn’t enough to explain why the Torah says גולגולת by pidyon haben, as this explanation isn’t relevant in that context
 Numbers 3:11-16,40-51
 See Mechilta parshas Yisro Masechta D’B’Chodesh § 9
 Rashi to Numbers 3:16