When taking a census of Am Yisrael, everyone over twenty was counted. The exception to this was Shevet Levi who was counted from one month old. What was the difference? The Avnei Nezer explains the following. There was the chait of the Aigel of which Shevet Levi did not participate. This demonstrated their great emunah in Hashem and Moshe Rabbeinu. The reason that Am Yisrael sinned was because their emunah was incomplete and they used their intellect instead to replace their faith. Moshe Rabbeinu said that he will return with the Luchos in forty days. Mistakenly, Yisrael counted the day Moshe ascended Har Sinai. When forty days terminated and according to their calculations Moshe did not return, immediately they set out to make an Aigel to replace Moshe. Shevet Levi however refused to follow the facts and math, but rather chose to proclaim that this must be human error. Instead, by sticking with emunah you will see that everything will work out just as planned. Sure enough Moshe Rabbeinu appeared the next day with the Luchos in his hand as he witnessed the wild dancing and the frenzy celebration around the Aigel. Moshe announced מי ליהו’ אלי Whoever is to Hashem draw close to me and Shevet Levi came to Moshe. מי לה’ (with kollel) is gematriah 107 the same as האמונה. This sends the message that their unflinching emunah merited them to be those appointed to do the avodah in the Mishkan and Beis Hamikdash throughout their generations.  

This is the reason why they are counted from thirty days old in contrast to the rest of Am Yisrael who were counted at twenty years old. The age of twenty is the age when an individual attains a matured intellect. That is why, at this age one can start to administer the punishment of Kares to those who transgress Hashem’s mitzvos. Klal Yisrael, who relied on their intellect through which they fell into chait by making the Aigel, were therefore counted in the census from the time of full bloom intellectual development. This was their modus operandi at that time: logic, statistics, mathematical proofs etc. However, Shevet Levi who replaced intellect with emunah and restrained themselves from worshipping the Aigel, were counted at thirty days old from birth. Emunah can be compared to a new born baby. Its brain is not yet developed and is not mature. It is like a functioning body without the ability to reason. Therefore a newborn with essentially only a body, is deemed a live viable entity at thirty days from birth as found in the mitzvah of Pidyon Habein which commences at the thirtieth day from birth. The meaning of the nameלוי  means to accompany. Shevet Levi never deserted the accompaniment of Hashem even when according to logic and rationale the matter at hand demanded a different response from what was originally planned.

The woman of Klal Yisrael excel in emunah more than the men as the Yaavetz writes that in the Spanish Inquisition the females sacrificed their lives more than the men who succumbed to forced conversion to Christianity. The Maharal writes that the word אמונה  is of the female gender as it ends with the vowel kametz followed by the letter ה. For the same reason they are prohibited to marry two men but nevertheless a man is permitted to marry two women. It is because a woman has naturally a greater degree of emunah and faithfulness to her husband than a husband would have to his wife. That is why the Torah allowed more than one wife to a man similar to the din of a Yefas To’ar (Devarim 21,11 Rashi).

With this we can explain that the seventieth nefesh who sealed the unit of seventy souls that descended to Mitzrayim, was Yocheved the mother of Moshe Rabbeinu. The seventy souls were parallel to the seventy nations as the passuk says (Devarim 32,8)יצב גבולות עמים למספר בני ישראל . The number 70 is ע. The letter ayin spells עין which means eye. An eye refers to wisdom as the leaders are called עיני העדה. The seventy nations of the world base their lives on intellect and knowledge. What cannot be proven scientifically in a laboratory is accepted as non truth. Emunah in Hashem does not exist by them. In contrast is Am Yisrael. Of course we value wisdom and intellect, after all that is what learning Torah is all about. But at the same time, emunah is the foundation of the Am Yisrael and the Torah. That is why the last individual to complete the seventy souls the nucleus of Yisrael was Yocheved a woman, who symbolizes emunah. יוכבד is gematriah 42 בם. In Shmah it says  ודברת בם  a mitzvah to converse in the words of Torah. The letter בם represents the acronym of the first letter of the Written Torah בראשית , and the first letter of the Oral Torah מאימתי. This teaches us that Torah is the embodiment of emunah represented by a woman. She represents the chasimah the seal of seventy ע and without emunah there cannot be true divine wisdom.

Emunah is compared to a scent that permeates. On the passuk (Bereishis 27,27)וירח את ריח בגדיו  Chazal say that Yitzchak smelled the scent of those who rebel against Hashem and yet they still possess the scent of Gan Eden on them. Their emunah is still strong enough to sacrifice their lives in order to make a Kiddush Hashem through emunah.

Shevet Levi differed in the census from the rest of Klal Yisrael, a distinction stemming from the chait of the Aigel. While the rest of Am Yisrael were counted with what makes sense by the senses at age twenty, Shevet Levi was counted with scents of emunah from newborns thirty days and up who possess little sense.   – Rav Brazil
Gut Shabbos