28th of Cheshvan, 5771
Although it is forbidden to activate an electrical appliance on Shabbat it is permitted to use or have a benefit from an electrical appliance that has been activated before Shabbat or that has been programmed before Shabbat to be activated on Shabbat.
This ruling is learned from the Mishna (2nd century, CE) where the Rabbis discussed a similar principle. They discussed, for example, if one can water his by activating the irrigation system before Shabbat and letting the water irrigate the fields during Shabbat. They also discussed if on Friday, one is allowed to set traps to hunt animals or nets on the water to catch fish during Shabbat.
The question is: are these 'personal' prohibitions, a person is not allowed to activate a device during Shabbat, or is it a 'device' prohibition (shebitat kelim), an object cannot be 'active' on Shabbat, even if it was activated or programmed from before Shabbat?
The conclusion of the Talmud is that the prohibition is for a person to activate his appliances or devices on Shabbat, but if these objects are activated or programmed from before Shabbat then, it is permitted to benefit from them.
In modern days, this principle is probably more relevant than ever, because many of our appliances could be activated automatically from before Shabbat.
The simplest example is a light timer. It is completely permitted to activate a light timer from Friday to turn on and off the lights on Shabbat.
For other appliances, there might be other things to consider, like noise, etc.
So, B'H next week we will learn about automatic appliances and their use during Shabbat.
Candle lighting for NY: 5:29
Shabbat ends in NY: 6:36
Rabbi Yosef Bitton. YMJC 130 Steamboat Rd. Great Neck NY 11024