Terumat ha-Deshen תרומת הדשן
354 sections in question-and-answer form—and most of the questions the author put to himself, so as to take a subject whole rather than as occasion brought it.
Responsa usually begin with someone else's letter: a question comes, an answer goes. Not here. Rabbi Israel Isserlein builds the book as an investigation: he poses the question himself, carries it through the Talmud and the Rishonim himself, and decides it himself. The result is not a collection of cases but a survey of a subject: there are three hundred and fifty-four such sections in all.
The real answers to real letters he gathered separately—the Pesakim u-Khetavim, 267 of which survive.
The year of composition is not recorded. This reference work gives 5220—the year of the author's death, that is, 'not later than'; the book was printed at Venice only in 1519. The Rema cites it constantly, and through the Mapah its rulings stand in present-day Ashkenazi practice.
On the timeline
Related
Sources
Rishonim
- Terumat ha-Deshen — 354 sections; the questions posed by the author to himself
Scholarship
- Encyclopaedia Judaica, "Isserlein, Israel ben Pethahiah" — the make-up of the book and the fact that the year of composition is not recorded
Basis: documents and evidence.