169061.

The ink had faded over the years, but it was distinct enough to read the numbers clearly: 1-6-9-0-6-1.

Given the fact that he taught physical education at Breuers, his short sleeve coach’s shirt did little to hide the tattoo that had been needled into his skin almost 80 years ago when he was six years old. Growing up in the South, I hadn’t met many survivors and had certainly never seen one with a number tattooed on his arm.

The first time I sat next to him, I could not stop staring at it. For the next 15 years, I looked at that number almost every day.

His name was René Slotkin, and I had the privilege of sitting next to him every morning, at seven o’clock, for a Daf Yomi shiur.

I learned from others that René and his sister, Irene, were Mengele twins, subjects of horrific experiments by the Nazis.

Whereas René was open about his experiences during the Holocaust, it was always nuanced, almost as not to overwhelm us as listeners. He would always accentuate the positive — survival, reuniting with his sister and being adopted together by a loving family, and building a life in New York with his beloved wife, June, his children and grandchildren.

He would show me his Gemara with his son’s handwritten notes in the margins; he could hardly contain his pride when he would read them years later during our shiur.

René was warm, friendly, encouraging and full of life. Everything he did was b’simcha, with happiness.

René was my inspiration, my role model of faith and belief.

Whenever I had questions or doubts about belief, religious observance or the hand I had been dealt with in life, I looked at the man with the tattoo sitting next to me who had no questions. In an interview with Eitan Katz, René recalls that he noted early on that from his point of view, the tattoo read: “190691,” totalling 26 when the digits were added together. He knew the gematria (Hebrew letter equivalent) of “26” to be the name of Hashem. Instead of seeing the tattoo as a tragic reminder, he saw it as a sign from God that he would survive. He also noticed that from an observer’s point of view (the way his number was registered by the Germans), the digits were flipped upside down, making the number “169061.” René realized that the sum of those numbers was only 23; he puzzled for years over what the number “23” could signify but always came up empty. Many years later, a friend from shul pointed out the significance of the 23rd perek of Sefer Tehillim. René finally understood that this was also a Divine indication that he had been protected through “the valley of the shadow of death,” in the same manner described by King David.

Over the years, I have reflected on René many times. I still find it staggering that a man who saw so much horror and devastation not only clung to his faith and belief, but did so with happiness and hakarat hatov.

Our tradition speaks of the “lamed vavniks” — the 36 righteous people in whose merit the world continues to exist. Now, I am by no means on the level to know who any of these people are. However, it is my humble opinion that my dear friend, René, met all the qualifications of a “lamed vavnik.”

For many years, I slept better at night knowing that a person like René Slotkin was around. I’m not sure if I will sleep as well anymore.

May his memory be for a blessing.

Dr. Jonathan Field, of Bergenfield, is a regular attendee of the early minyan at Ohab Zedek in Manhattan.