Kol Nidrei כל נדרי
The Aramaic annulment of vows that opens Yom Kippur—a prayer the Geonim argued against and the people kept.
It is not a prayer strictly speaking but a court formula: before Yom Kippur begins, the community declares rash vows void—only those between a person and Heaven; debts and obligations to people Kol Nidrei does not touch, as the law itself states.
The first evidence is from the Geonim, and many of them objected: Rav Amram Gaon called the custom foolish. The people did not yield. Later it was told that Kol Nidrei was the prayer of the anusim, Spain's secret Jews renouncing forced oaths—a beautiful tradition, but the prayer is older than those persecutions. The Ashkenazi melody of Kol Nidrei is among the most recognisable in the Jewish world: with three swelling repetitions begins the strictest day of the year.
On the timeline
Related
Sources
Chazal: Mishnah, Talmud, midrash, Zohar
- Nedarim 23b — annulling vows in advance
Rishonim
- Seder Rav Amram Gaon — the Geonim dispute the custom
Basis: tradition.