Rabbi Menachem Mendel Taub, the Israeli-based Grand Rabbi of the Kaliv Hasidim, died at age 96 on April 28 at his home in Jerusalem. His funeral took place the same day, and thousands of Hasidim came to mourn.

A Holocaust survivor, Rabbi Taub devoted himself to exhorting the Hasidic world and those outside it to remember the approximately six million Jews killed by the Nazi regime during WWII. He also reached out to less observant Jews to reconnect them with their faith by urging them to recite the Shema Yisrael prayer regularly, leading such recitations himself.

According to the New York Times, Rabbi Taub was born in 1923 in the Transylvanian town of Marghita, now in Romania. He had six siblings. His father, Rabbi Yehuda Yechiel Taub, was a prominent Hasidic leader.

The family was deported to Auschwitz in 1944, and all six siblings were killed. Rabbi Taub was subjected to chemical experiments by Mengele that left him sterile. He spent time in other concentration camps, including Bergen-Belsen. After liberation, he was reunited with his wife, Hana Sara, in Sweden, The Times said.

According to the London-based weekly newspaper, The Jewish Chronicle, Rabbi Taub was once asked why the recitation of the Shema prayer was so important. He replied that just before he was liberated at Bergen-Belsen, Nazis had been throwing Jews into burning pits.

“I cried out the Shema Yisrael and said: ‘Ribbono shel Olam (Creator of the World), this might be, God forbid, the last time I will be saying Shema Yisrael. Soon I will be with the rest of my family in heaven. If you give me life, then I promise You that I will say it time and again…”