Rabbi Dr. Moshe Dovid Tendler Passes at the Age of 95

By: Cayla Muschel  |  October 3, 2021

By Cayla Muschel, Arts and Culture Editor

Editors Note: The following article has been modified to include a comment from Dr. Chaim Nissel.

Rabbi Dr. Moshe Dovid Tendler passed away on Shmini Atzeret [eighth day of the Sukkot holiday] last week, at the age of 95.

Rabbi Tendler, son-in-law of Rav Moshe Feinstein, was a renowned posek [halachic authority] and scientist. To many, he is remembered best for his works which integrated his halachic expertise with his scientific knowledge. 

Rabbi Tendler was born on the Lower East Side in 1926, and earned a PhD from Columbia University in microbiology and semicha [rabbinic certification] from YU. In addition to Rabbi Tendler’s position as a senior Rosh Yeshiva at YU, he taught Talmud, introductory and advanced biology courses, and conducted research, developing a cancer drug, Refuin. Rabbi Tendler was a leading expert on Jewish medical ethics and wrote about complex medical issues in halacha including euthanasia, end of life issues, and organ donation. 

Rabbi Tendler met his future wife, Rebbetzin Shifra Tendler —Rabbi Moshe Feinstein’s daughter— while Rabbi Tendler was a student at RIETS; many of Rabbi Feinstein’s halachic responsa are addressed to Rabbi Tendler. His relationship with his father-in-law and scientific knowledge was a strong contributing factor in Rav Feinstein’s famous halachic ruling on brain death and organ donation. 

Rabbi Tendler was the leader of Community Synagogue in Monsey for over fifty five years, and is remembered at YU for his eighty years of involvement with the university. Rabbi Tendler attended MTA as a high school student, and continued on to attend RIETS and NYU simultaneously, earning semicha and a bachelor’s and masters’ degree in biology while teaching shiur at MTA. Rabbi Tendler proceeded to teach Biology at YC and ascended the ranks at YU, eventually becoming a Rosh Yeshiva at RIETS. He continued to teach shiur at RIETS until this past year, despite continued health difficulties. Speaking at the funeral, Rabbi Hershel Schachter, Rosh Yeshiva of RIETS and personal student of Rabbi Tendler, said that “[Rabbi Tendler] gave his whole heart and soul to the yeshiva.”

“As a renowned scientist, beloved communal leader, and preeminent rabbinic decisor, Rabbi Dr. Moshe Tendler embodied the Torah values of our community and successfully lived a life of deep learning, commitment to others and spiritual authenticity,” shared President Rabbi Dr. Ari Berman in his statement to the YU Observer. “The Jewish community and the broader society were elevated by his leadership, and his absence is a loss for us all.” Dr. Chaim Nissel also expressed to the YU Observer that “Rabbi Moshe Dovid Tendler ZT”L was a giant in Torah and at the same time he was very approachable and personable. The Hespedim at his funeral were inspiring and I encourage everyone to listen to them. I am grateful for the decades long personal relationship I had with him.”

In his eulogy at Rabbi Tendler’s funeral, Rabbi Dr. Berman said, “In the world of Torah Umadda [Torah and science, YU’s motto], Rabbi Tendler removed the vav [sixth letter of the Hebrew alphabet] and fully integrated both aspects into his life…it was who he was. For all the ways in which his sefer helped shape our own, he will be sorely missed.” 

Rebbetzin Tendler passed away in 2007. Rabbi Tendler is survived by eight children and over a hundred grandchildren and great-grandchildren.