Shavuot is a curious holiday. On the one hand, it commemorates the giving of the Tora, the central event in Jewish history. The moment the whole exodus thing leads up to. But on the other hand, there are no real big traditions, customs or even symbols. The only two things people will tell you about the holiday are "stay up late to study" and "eat dairy". I think this is really fascinating that what should be the most important holiday is no … nondescript, but I cannot think of an answer why.
So, let’s go to the question I can answer: why do we eat dairy on Shavuot? This is actually a prime example for "there is not the one answer" – there are lots! Here some examples of reasons that came up during Shavuot dinner (I tried to find a source in the internet for each):
- The Jews just received the Tora and the laws of kashrut, they didn’t have any kosher meat/kosher pots (Aish, reason 1, Chabad, reason 2).
- The Tora is compared to milk (Aish, reason 2, Chabad, reason 3).
- Chalav, the Hebrew word for milk, has the numererical value 40, equivalent to the number of days Moshe spent on Mount Sinai (Aish, reason 3, Chabad, reason 3).
- It is the time of the year that goats give lots of milk (Tzvee Zahavy).
- After receiving the Tora we are like babies who can only drink milk (Ozzie Nogg).
Some other reasons I have read are referring to two meals, one dairy and one meaty, that are eaten on Shavuot. I have never heard about this custom, have you? Here are the reasons:
- The negative commandment corresponding to the day of Shavuot is "don’t cook a kid in its mothers milk" – we eat a dairy and a meaty meal separately (Aish, reason 4).
- We eat a dairy and a meaty meal to be forced to use two loaves of bread, alluding to the two loaves brought in the temple for Shavuot (Chabad, reason 1).
There are some other reasons that can be found on other pages – I think no other custom has so many colorful explanations. So have fun inventing your own reasons and chag sameach (belated)!