I received the following question:

Why does there seem to be so few Levites compared to the other tribes?

Levi seems to have been a particularly bloody and wicked man. In Genesis 34:25, he, along with Simeon, is the one who gets revenge for the ruining of his sister by wiping out all the men in the town where the man responsible lived! In Jacob’s proclamation concerning his twelve sons, Levi and Simeon are spoken of together, and do not receive a good word from the LORD.

5. “Simeon and Levi are brothers;
Instruments of cruelty are in their dwelling place.
6. Let not my soul enter their council;
Let not my honor be united to their assembly;
For in their anger they slew a man,
And in their self-will they hamstrung an ox.
7. Cursed be their anger, for it is fierce;
And their wrath, for it is cruel!
I will divide them in Jacob
And scatter them in Israel.

This curse upon him seems to have resulted, among other things, in Levi being less “fruitful” and having fewer offspring than his brothers.

However, the fate of Levi was largely reversed in the wilderness at the incident of the golden calf. In Numbers 32:26, we read of it.

26. then Moses stood in the entrance of the camp, and said, “Whoever is on the LORD’s side—come to me!” And all the sons of Levi gathered themselves together to him.

Because of their faithfulness in this case, it seems that what had initially been a curse upon Levi was turned into a blessing. They were divided in Jacob and scattered in Israel, but now it was because they were made God’s special tribe, and they were scattered among their brethren so that they could serve the LORD by ministering to and teaching the people wherever they lived.

So the low number of Levites was probably initially because they were not in favor with the LORD. Even when their curse was turned into a blessing, the trend of low numbers compared to the other tribes seems to have continued. Since they were a priestly class, they were often better educated than the rest of the Israelites, and educated people often have fewer children, for whatever reason. Other than that, I cannot say much about why this trend continued. Perhaps it is simply that the LORD wanted them to remain smaller than the other tribes.