Whatever else you’re doing of an evening, don’t phone a friend just before eight o’clock.

“Can’t talk now,” is what you’ll be told. “I’ve got a shiur starting in two minutes with Rabbi This.”

@OK, I’ll call back in an hour.

“No, we’re doing Rabbi That’s laws of Pesach.”

Ten o’clock any good?

“No, that’s when Rabbi Tother comes online from Monsey with his nightly Q&A.”

Few aspects of our enforced isolation have been so astonishing as the resurgence of the rabbinic shiur, the timeworn forum of Jewish learning. It is no exaggeration to state that we are in the grip of a pandemic of shiurim, a phenomenon unwitnessed since the Golden Age of Pumbedita, or the shtetl.

There is a shiur for every purpose under heaven and it is thronged by an online waiting list longer than Waitrose at eight in the morning. Why this is so I can’t fully explain, but since the JC’s resident shrink has been whisked into scrubs at Northwick Park hospital I’ll do my best to fill in (and yes, there’s at least one shiur going on tefillin).

We’re talking here of some dark emotional need and residual marital remedies. In the strictly-Orthodox shul where I grew up they used to say that it was no disaster if a married couple stopped speaking to each other. She would be occupied with the kids, the household and neighbourly concerns and he’d be our at his shiur.

On the seventh night, Friday, he would spend the whole mealtime testing the kids on the Torah they had learned that week at school. No need for the estranged couple to exchange more than “pass the chrane”. After a month or three, someone would break the silence and they’d remember they still loved each other. Saved by the shiur. Just what the rebbe ordered.

What goes on at a shiur is nothing much. A bunch of men, mostly married or otherwise depleted, hunch over a page of Talmud designed by Joshua Solomon Soncino back in 1483 while a rabbi splits the minutiae of an argument that took place 1,000 years before printing.

No refreshment is taken at a shiur, except on winter night a glass of lemon tea at the shiur-giver’s elbow, and whatever conflict arises in the discussion is mostly a matter of mutual reassurance rather than confrontation. The atmosphere is more like the Athenaeum lounge during Harold Macmillan’s premiership than the coffeeshops of Fleet Street in the age of Swift and Addison.

After an hour or two last tome is shut and kissed good night. Everyone then toddles off home happy in the knowledge that they have performed the mitzvah of keviat ittim — fixing a regular time for Torah. It must be where Freud got the idea of the 50-minute hour — same patient, same appointment time.

What’s happening now, however, bears no resemblance to these slumberous meetings. I’m hearing of hardcore Talmudists who have thundered for two decades against the evils of the internet slipping discreetly online with herd immunity to give come-one, come-all shiurim around the clock.

Beards who a month ago did not know Facetime from gefilte fish are now dancing between social media like Nureyev on hot coals. If you see the rebbe squinting in a shiur, it’s not at the small print of Rashi but at questions that are coming in at him thick and fast on live chat.

Live chat? If the Prophet Elijah walks through the door on the Seder night, throw a matzah cloth over the Instagram so he can’t see all your isolated friends who are taking part on remote.

The demand is getting to be overwhelming. I tried to watch Rabbi Joseph Dweck one night on Zoom, only to find it can only take 100 participants and getting shoved down into the overflow on his Facebook page.

Upset? I should say. My regular Talmud teacher got hospitalized with a spot of CV-19 (he’s fine, TG), so I have drifted onto Rabbi Johnny Solomon’s Facebook daf yomi, which is pretty good. He also plays a mean piano.

Women are doing shiur as much as men, generally with greater intensity. No way will they ever be closeted again behind a latticed partition. The online shiur has changed everything.

Never in the field of human isolation was so much Torah taught to so many. I could tell you more but I just touched base with my best mate in Jerusalem, a rabbi-turned-psychotherapist, and he’s rushed off to teach liberation theology on Zoom. It’s his first online shiur. How liberating is that?