For this reason no supplications are offered on any of the days of Nisan and there is no fasting until Nisan has passed. The only exception is [the fast of] the firstborn (Ta’anit Bekhorot) who fast on the eve of Passover.
For this reason no supplications are offered on any of the days of Nisan and there is no fasting until Nisan has passed. The only exception is [the fast of] the firstborn (Ta’anit Bekhorot) who fast on the eve of Passover. -Tractate Soferim...



