The Magen Abraham (Rabbi Abraham Gombiner, Poland, 1637-1682) established an important rule relevant to the prohibition of Amira Le’akum – asking a non-Jew to perform on Shabbat an act which is forbidden for Jews. Asking a gentile on Shabbat to perform such an act is generally forbidden, but the Magen Abraham rules that this prohibition does not apply if the violation is an unintended byproduct of an inherently permissible act. For example, if somebody forgot to turn off the refrigerator light before Shabbat, he would be allowed to ask a non-Jew to open the refrigerator for him on Shabbat so he can take out food. A Jew may not open the refrigerator in such a case, as this act will inevitably result in the light turning on. And although the Jew has no intention to turn on the light, it is nevertheless forbidden to open the door because this is a situation of "Pesik Resheh" – where the violation will inevitably occur. A Jew may not open the door in this case even for the sake of a Misva, such as to take out food for the Shabbat meal. However, according to the Magen Abraham, although a Jew may not open the door, he may ask a non-Jew to open the door for him. Since he does not ask the gentile to perform a forbidden act, but rather that the door be opened, the request may be made even though the act will inevitably result in the light turning on.
Another common example is opening a car door. If somebody needs something from the car on Shabbat, such as if he forgot to bring in the food or drinks from the car, he may ask a non-Jew to bring him the items from the car on Shabbat, even though by opening the door the non-Jew will turn on the light. Since the Jew is asking the gentile to perform an inherently permissible act – opening a door – he may make this request even though this act will inevitably produce a result that is forbidden for Jews on Shabbat.
Hacham Ovadia Yosef, in several places (Yabia Omer vol. 4 and vol. 7 38:2, and Hazon Ovadia – Shabbat, vol. 3), accepts this lenient ruling of the Magen Abraham. He adds that this Halacha applies as well to turning on hot water on Shabbat. It is forbidden to turn on the hot water on Shabbat because this causes cold water to go into the boiler where it is heated. Even though one has no intention to heat cold water when he opens the tap to obtain hot water, this is nevertheless forbidden because it inevitably results in water being heated. However, it is permissible to ask a non-Jew to turn on the hot water on Shabbat, since the non-Jew is being asked to perform an inherently permissible act, and the violation is only an unintended consequence of this permissible act. And thus, for example, if somebody wants to wash his hands with warm water on Shabbat, although he may not turn on the hot water, he may ask a non-Jew to open the hot water for him.
This Halacha is also discussed by Hacham Ovadia’s son, Hacham David Yosef, in his recently-published work on the laws of Amira Le’akum (pp. 79, 81-82). Hacham David emphasizes that although one may ask a non-Jew to turn on the hot water, it is forbidden to ask a non-Jew to heat water directly, such as on the stove, because, as discussed, it is only when the violation occurs as a consequence of an inherently permissible act that Amira La’akum is allowed.
Summary: Although it is forbidden to ask a gentile on Shabbat to perform an act which is forbidden for a Jew, one may ask a non-Jew to perform an inherently permissible act which results in a violation. For example, if one forgot to turn off the refrigerator light before Shabbat, a Jew may not open the door on Shabbat, but he may ask a non-Jew to open the door for him. This applies to opening a car door, as well. By the same token, even though one may not turn on the hot water on Shabbat, he may ask a non-Jew to do so.
