Rabbis from Jerusalem and other cities have called for people not to travel from one city to another on Friday, or to leave only during the morning hours.
This year, Purim for most of Israel is celebrated on Friday, though in Jerusalem and a few other cities, there is a "triple Purim" spread over Friday, Saturday, and Sunday.
The warning not to travel comes amidst concerns that there may be traffic jams on the highways.
"Experience from previous years has taught that the roads when Purim falls out on Friday become overwhelmed and especially congested, which may cause Sabbath desecration," the letter read.
The rabbis especially asked residents of Jerusalem to open their homes to those asking for money and donate on Sunday as well, so as to avoid a situation in which those collecting money feel a need to travel to Jerusalem specifically on Friday.
The letters are being distributed in haredi communities, as part of the effort to preserve the sanctity of Shabbat (the Sabbath) during the holiday.