http://revach.net/article.php?id=5071

Section: Parshas HaShavua   Category: Numbers & Letters
Parshas Bamidbar - Rav Michel Feinstein - Shevet Levi Was The Fastest Growing Population

The Ramban makes a calculation that Shevet Levi had less than one half the population of the smallest Shevet. He asks how could it be that Shevet Levi, the Avadim and Chasidim of Hashem, did not multiply at least as fast as the other Shevatim? He answers that the astronomical growth of Bnei Yisrael was due to their Shibud in Mitzrayim which Shevet Levi was not a victim of.

Rav Michel Feinstein makes a calculation that comes to the opposite conclusion. Rashi (Bamidbar 3:39) makes a calculation that Shevet Levi had 300 Bechorim. Out of a population of 22,300 Levi'im above the age of thirty days that means they had an average of approximately 70 children per family! The rest of Bnei Yisrael had 22,273 Bechorim out of a population of 603,550. Even if you double that to include the ones younger than 20 years old you, still have an average family size of around 50, which is far less than the average Levi family.

If so, why did Shevet Levi have such a small population? The Ohr HaChaim HaKadosh says that eighty years before the Yetzias Mitzrayim the Levi'im divorced their wives because of the gezeiros. ("Although Amram took his wife back, the others did not," says the Ohr HaChaim). Therefore, Bnei Levi were far behind in raw numbers. "As proof of this," says the Ohr HaChaim, "in the census taken later in Divrei HaYamim, Bnei Yisrael did not even double, but fast growing Shevet Levi, more than quadrupled during this period."