This powerful prayer is said to have been first published in the 11th century by Rabbi Kolonymus of Meinz, although it was not composed by him but by a Rabbi Amnon.

The story is that Rabbi Amnon was a wealthy sage, who for years had been pressured by the local authorities of Meinz to change his faith. Once, as a stalling tactic, he asked them to give him three days to think about it, only to realize that this created the impression that he might renounce his faith. Brokenhearted at the thought of what he had done, he cried inconsolably, and he could not eat nor drink.

When the rulers discovered that Rabbi Amnon had no intention of converting, they arrested him and punished him by cutting off his hands and feet. Dying from his wounds, he was brought to the synagogue on Rosh Hashanah, and just before the Kedushah, he asked the congregation to pause; he then recited Unesane Tokef, which begins, “Let us describe the great holiness of this day.” As he ended this prayer, his beautiful and holy soul ascended on high. A few days later, he appeared to Rabbi Kolonymus in a dream and taught him his prayer so that it could be introduced to all congregations.