Israel Isserlein

Even though Regensburg in Bavaria is often quoted in literature as Isserlein's birthplace it is now clear that he was born in the Styrian Maribor, present-day Slovenia, in the last decade of the 14th century.

His grandfather Rabbi Chaim, named Henschel of Hainburg or Hetschlein of Herzogenburg was well-versed in Jewish learning, which held especially for Isserlein's great-grandfather R. Israel of Krems.

With his wife Schoendlein he had four sons named Petachia (Kachil, Khatschel), Abraham, Shalom, Aaron, and a daughter Muscat, who died in her childhood.

Responsa of rabbis Israel Bruna, Moses Mintz and Jacob Moelin or the Maharil of Mainz quotes Isserlein with great respect.

He is considered as an ideal type of medieval rabbi, who demanded from the community and its members a strict observance of ritual laws, social justice and fairness in business and commerce.

The work is named for the practice in the Temple in Jerusalem of removing a part of the previous day's ashes from the furnace – 354 is the numerical value of Deshen (Hebrew: דשן).

The work was therefore used by R' Moses Isserles as one basis for HaMapah – the component of the Shulkhan Arukh which specifies divergences between Sephardi and Ashkenazi practice.

Therefore (Shach concludes) unlike with other responsa, the parameters of the questions posed in the Terumat HaDeshen are themselves binding when alluded to in the answer.