Rabbi Aryeh Lebowitz

There was, in the early part of the 20th century, there was a major movement to try to get an Erev established,

in Manhattan, and the core issue about whether or not you can have an Erev in Manhattan, or anywhere for that matter, is whether that area, it constitutes a Rosh Hashanah Rabim mida or raisa.

In the Siman Reshman Hay in Ar Chaim, the Shulchan Aruch goes through the definition of a Rosh Hashanah Rabim, and quotes two deos, two opinions, whether part of the definition of a Rosh Hashanah Rabim is that there needs to be 600,000 people there.

If you do not need to have 600,000 people there for something to be a Rosh Hashanah, that is a chumrah.

If you need to have 600,000 people there for something to be considered a Rosh Hashanah, that is a kula.

So the Mishabur writes, we don't like that kula.

We don't like the suggestion that something is not a Rosh Hashanah just because it doesn't have 600,000 people there.

But we cannot make a macha'a against those who do rely on that suggestion.

Now, so Rav Moshe and all the others would not have had a problem with it, would not have had a problem with it, I mean they may have had a problem with it to rely on it themselves, but they certainly would not have publicly said anything probably if it didn't have 600,000 people there.

Because then at least you're relying on the opinion that holds that it's not a Rosh Hashanah if it doesn't have 600,000 people.

Problem is Manhattan does have 600,000 people.

So this became a matter of a lot of discussion in the post.

Rav Moshe happens to say...

That 600,000 people does not mean you need 600,000 people to go down the street.

I should add that an area that has two walls, which all of Manhattan does because there are a lot of buildings on the streets, and those buildings make up walls down each street.

It's definitely more building than open space.

would not be Rosh Hashanah unless it's open on both ends.

And that's where you run into a problem, that it's open on both ends.

So anyway, Rav Moshe says 600,000 people doesn't mean 600,000 people on the street.

It means 600,000 people in the area, 600,000 people that live in the area.