And all believe that He is the faithful G‑d... — Rosh Hashanah Musaf Prayers.

Mendel spent 14 years in hard labor camps because of his involvement in the Jewish underground in Stalinist Russia. The camp authorities knew that he would not perform ordinary work on the Jewish holidays, so they gave him chores that did not involve forbidden tasks.

That was the extent of their tolerance. They did not provide him with time to pray or a prayer book. Once on Rosh Hashanah, while Mendel was doing the chores he was given, he was singing the holiday prayers to himself.

While he was reciting the Musaf service and singing the hymn V'chol Maaminim, which declares how all men share in the belief in G‑d, he stopped and thought: Why was he in a hard labor camp? Because there were people who did not believe, and whose unwillingness to believe was so fierce that they tried to crush — both physically and spiritually — those who did.

As he was thinking, he noticed one of the guards looking at him closely. The guard was tall and imposing. He had a scar running across his face that made him look particularly threatening. With such a person eyeing him, it was better not to take time out to think. Mendel returned to his chores and shortly afterwards, the guard moved on.

On Yom Kippur, as Mendel was going about his assigned chores, he saw the guard with the scar approaching. With a few deftly planned steps, the guard maneuvered Mendel into a corner where no one else could see or hear what they were saying.

"Are you fasting today?" the guard asked Mendel.

Mendel answered affirmatively. There was no way he could deny it; his observance was common knowledge.

"So am I," the guard continued. "Ten days ago, I heard you chanting a tune and it brought back memories of my father taking me to synagogue as a child. I realized that it was Rosh Hashanah, and I counted the days until Yom Kippur. I am also fasting."

Mendel and the guard both sensed that others might be looking, and each turned to go his way. But Mendel's quandary had been solved. He proceeded, humming the tune V'chol Maaminim — "All Believe."