(CNN) When a man with a "big machete knife" burst into a rabbi's home, stabbing victims as they celebrated Hanukkah, Josef Gluck ran away from the danger.

Then he came back to confront it.

Josef Gluck

It was Saturday night, and dozens of people had gathered at Rabbi Chaim Rottenberg's home in Monsey, New York.

The congregants spanned generations, from 2 months old to 80 years old. About 20 of the youngsters were the rabbi's own grandchildren, Gluck told CNN's "New Day" on Monday.

As the rabbi was finishing the candle-lighting ceremony, "the attacker came in ... with his big machete knife," Gluck said.

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