It is the custom to release vows on Rosh Hashanna… Here, in the city of Safi, the custom has been to release vows on the 19th of Av, forty days before Yom Kippur, because it says in the holy Zohar that "Banishment or censure decreed by the Court of Heaven lasts forty days, and the prayers of whoever has been banished are not heard." The release of vows, therefore, is done forty days before Yom Kippur, after which time much care is to be taken not to do anything that deserves banishment.