This has got to be the strangest thing that Hasidim do and they do a lot of strange things.
Some of you might have seen Slate magazine which had a piece [by Benyamin Cohen] that came out yesterday on this practice. If you know my article on the topic, you’ll recognize that he took much of his article from there but that’s OK, even though I didn’t get mentioned.
This practice was followed hundreds of years ago in Italy, so obviously this is not Hasidic nonsense.
The notion that you don’t study Torah on Christmas Eve is not found in the Talmud or in rabbinic literature.
The term “Christmas” never appears in rabbinic literature. It is forbidden by Jewish law to mention the name of an idolatrous holiday when this name expresses the foreign god’s lordship. Yet all poskim say there is no problem saying the word “Christmas.” It means Christ’s mass. But the word “Christ” means Moshiach aka the anointed one. Jews should not refer to Jesus as “Christ.”
Because Jews were traditionally persecuted by Christians, there was a visceral dislike, in a way we don’t have today, for all things Christian.
Chaim Soloveitchik points it it would’ve been very easy for the rabbis to permit non-Jewish wine. After all, non-Jews don’t offer their wine to idols. The rabbis were able to permit dealings with Gentiles in opposition to what the Talmud says.
Today wine is drunk occasionally because we enjoy it. Wine used to be a staple. Water was unhealthy. The way we drink water, they drank wine. Not having involvement in non-Jewish wine — not drinking or selling or transporting — with non-Jewish wine was a huge economic burden. The rabbis could’ve found a way but as Chaim Soloveitchik points out, this shows the visceral dislike of Christianity and why they keep away from non-Jewish wine.