Shabbat 34–35 discusses the laws of
bein ha-shemashot, the period of twilight between sunset and full darkness. This time has a status of
safek, uncertainty, when it comes to laws that depend on the time being day or night. There was no way I was going to skip a
sugya on
uncertainty.
A
berayta on 34b states:
תנו רבנן: בין השמשות ספק מן היום ומן הלילה, ספק כולו מן היום, ספק כולו מן הלילה - מטילין אותו לחומר שני ימים.
Bein ha-shemashot is a three-sided
safek: it might be fully day, it might be fully night, and it might be some combination of the two. In any question of
halakhah we treat it stringently, as either one, or the other, or both of the days that it bridges.
There are two main
shittot on understanding the side of the
safek that
bein ha-shemashot could be both days. Rabbeinu Tam understands the
safek to be that any moment between sunset and nightfall could be the dividing line for when the previous day ends and the new day begins. The Ritva (as understood by some
aharonim based on a comment on
Yoma 47b) understands the
safek to be that the entire period of
bein ha-shemashot might be ruled as both days intertwined, just as an
adroginus might be ruled both male and female.
In this post I discuss Rashi's
shittah on how this
safek works. It's a
shittah whose meaning is, well...uncertain.