Q: How many frum Jews have to care for a cow? Well, Shmuel Shtroiman lives on a farm, and he has to feed the cows every day - including on Shabbos! Shmuel takes the straw from a pile and places it into a large container, which he then carries to the trough for the cows to eat.
One Shabbos, Shmuel discovers that the usual container he uses is not next to the pile of straw. All he can find is a large basin with holes on the bottom, which is used to shake the small pieces of garbage from the straw meant for the cows.
Shmuel is concerned, since if he places the straw inside the container, some of the garbage pieces will fall out, which is borer. While he's not trying to do this, it's a psik reisha, a melacha that will definitely happen through what the person is doing, which is forbidden.
What should Shmuel do?
A: According to some opinions, Shmuel may put the straw into the basin even though the garbage pieces will fall through the holes. This is not considered a psik reisha according to this opinion, as his action is not the one causing the melacha to happen - the borer happens on its own as the pieces fall through the hole on their own.
Other opinions, however, say this is still considered a psik reisha and is forbidden.
To avoid the sha'ala, it is proper for Shmuel to find a different container without holes.
(בורר, התירים, פרק ב‘, סימן ד‘, סעיף י“א, דוגמא 2)
