Arnon Shimshoni, in Haaretz, discusses this story ("The Sign") and the other characters who appear in it, who were based upon real people whom Agnon knew in Jerusalem.
Agnon describes a mystical experience that he had on the eve of Shavuot 1943 in the wake of the first reports about the destruction of his birthplace, Buczacz. According to Elior, Agnon’s description of the experience both imitates and continues the prophet Ezekiel’s description of the mystical revelation that he had on the eve of Shavuot, and similar experiences that prominent kabbalists such as Joseph Karo, Nathan of Gaza and Moshe Chaim Luzzatto experienced on the same date.
The Sign describes two challenges and two worlds, both of which make their appearance in the opening sentence: “In the year when the news reached us that all the Jews in my town had been killed, I was living in a certain section of Jerusalem, in a house I had built for myself after the disturbances of 1929 (5629 – which is equal, numerically, to ‘The eternity of Israel’).” “My town” is the Galician town of Buczacz, which was destroyed utterly, and whose memory is preserved in the layers of memory. “A certain section of Jerusalem” is the neighborhood of Talpiot, of which Agnon was one of the earliest inhabitants.
Buczacz, with its halls of religious study and large synagogue, is destroyed, its Jews dead. To the author’s sorrow, in the story they gradually vanish from his memory. It takes a mystical experience, the mobilization of the poet Solomon ibn Gabirol on Shavuot eve, to give Agnon a sign so that he will not forget the town’s name. On the other hand, the neighborhood of Talpiot, in whose synagogue Agnon had the mystical experience on Shavuot eve, is real. “From the day we were exiled from our country, only thorns and thistles grew from this soil. Now that we have returned, it has been built up with houses and trees and bushes and flowers.” The year of the riots, when Talpiot was attacked, Agnon’s rented apartment was looted and his books scattered to the four winds – was 1929: in gematria [a system that assigns numerical values to a Hebrew word or phrase], the Hebrew letters denoting the year 1929 are equivalent to the biblical phrase “netzah Yisrael” [the eternity of Israel]. After the riots, Talpiot was rebuilt, and Agnon’s new home was built there.