Orthodox Community at Penn

The prohibition of amirah l'akum is telling a non-Jew to do one of the 39 prohibited activities for a Jew on Shabbat. Although it is a Rabbinical ordinance, it has a Biblical source and is therefore considered a severe (and quite common) Rabbinic prohibition.
In order to employ a non-Jew to do a melachah (prohibited activity) on Shabbat, there are two separate restrictions that must be borne in mind. Only when neither of the restrictions applies is it permitted for a non-Jew to do work for a Jew on Shabbat. The two restrictions are:
1. To command a non-Jew to do any work that would be prohibited for a Jew to do on Shabbat. The command may not be made either on Shabbat or before Shabbat:
2. To benefit directly from work done by a non-Jew for a Jew on Shabbat, even if the non-Jew was not commanded to do the work. Our Sages enacted this prohibition so that a person will not be tempted to transgress this prohibition of amirah l'akum and ask a non-Jew to do a melachah directly for him.
Consequently, one can only benefit from the activity of the none Jew if (1) the non-Jew was not commanded to do the activity by the Jew, and (2) the Jew will not directly benefit from his work.

II. HOW DOES ONE AVOID THE FIRST RESTRICTION - COMMANDING THE NON-JEW?

This prohibition can be avoided if the non-Jew understands what he has to do without being explicitly commanded. The Jew may hint to a non-Jew what he wants done, but the hint may not be in the form of a command. For example, it is permissible to tell a non-Jew: "My bedroom lights are on and I will not be able to sleep"; "It is a pity that so much electricity is being wasted;" "The food on the stove is burning" etc. In such a fashion, you are telling a story, not asking for his services. You may even say, "you know last week when we had the same situation you didn't turn off the light!"
It is forbidden, however, to add: "Will you please help me out?" since then the hint is accompanied by a form of a command. Even if the non-Jew asks: "Should I turn the light off for you?", it is forbidden to answer: "Yes," but rather the most you can say is "if that's what you think should be done."
Non-verbal hints in the form of a command are prohibited even if no words are exchanged and one merely gestures or nods.

III. HOW DOES ONE AVOID BENEFITTING DIRECTLY FROM A NON-JEW?

As we mentioned before, our Sages prohibited only direct benefit, such as a non-Jew turning on a light or cooking food - you may not get benefit from the light (meaning you must leave the room) or the food (you cannot eat that food). But, there are three categories of permissible benefit, namely: indirect benefit, additional benefit, and for a mitzvah. Let us explain those terms:
[1] Indirect benefit is when the benefit is not a direct result of the prohibited activity, but a by-product of it; when the prohibited activity removes an obstacle which then enables one to benefit from something. For example: Putting out a light in a bedroom does not directly enable a person to sleep; it merely removes the light which until now made it difficult for him to fall asleep. Similarly, shutting off the air-conditioning or radio alarm.
[2] Additional benefit is when a benefit was previously available to some extent, but the prohibited activity performed by the non-Jew makes it easier to do that which was possible to do even without the prohibited activity that the non-Jew did. For example: Additional lights are turned on by a non-Jew in a room which is already lit, or a dim light is switched on to high.
[3] A third exception to the prohibition against gaining benefit from the act of a non-Jew is when the non-Jew was asked to do a prohibited activity on the Shabbat for the sake of a public mitzvah (such as the lights are off in the synagogue, the janitor can be asked) or for the sake of a sick person. In such a circumstances, although one may not command the non-Jew, but must hint to them (the first prohibition) one does not have to worry about the 2nd prohibition of gaining benefit.

IV. SOME PRACTICAL APPLICATIONS & EXAMPLES:

1. A non-Jew, without being told, turns on a light in a dark room for the benefit of a Jew. It is forbidden to read in that room or to derive any other use from the light, since the benefit is new and direct. If however, the non-Jew turned on the light solely for his own benefit, then the Jew may benefit from the light.
2. In the case of a public mitzvah, such as the lights or air-conditioning being off in the synagogue, one may hint to a non-Jew to help with the situation. Similarly, if one forgets to turn off the light in one's refrigerator which contains all the food for one's Shabbat meal.
3. in the case of a sick person, one may ask the non-Jew to do something even directly, as the value of healing the sick overrides. This applies to anyone who cannot get out of bed or is dangerously ill, and would thus apply to anyone who is in the hospital.
4. A non-Jew turns off the light in a bedroom. One is permitted to sleep there since he is benefiting indirectly. It is not permitted, however, to instruct the non-Jew to turn the light off.
5. A non-Jew, without being told, turns on a light in a dimly lit room so that the Jew can see better. The Jew may continue using the room for whatever use he was doing before the non-Jew turned on the light, even though it is now much easier for the Jew to work in the room.
6. A room is lit by faint, natural daylight. If a non-Jew turns on an electric light, the Jew may continue using the room as long as there is some degree of daylight. Once it turns dark, however, the non-Jew's prohibited activity is producing new, not additional, benefit. It is, therefore, prohibited to derive any benefit from the light that was turned on.
7. It is prohibited to hint to a non-Jew that it is hot in the room, hoping that he will turn on an air conditioner, since the benefit that the Jew will have from the air conditioner, cool air circulating in the room, is direct and new.
8. In the case of an entrance with an electronic eye, although one may not ask a non-Jew to open the door for him/her, one may wait until a non-Jew walks through, thereby opening the door for him or herself, and once it is open the Jew may follow them in immediately. The same is true for a light that turns on automatically in the staircase.
9. It is also permitted on Shabbat to ask a non-Jew to wash dirty dishes knowing full well that the non-Jew will use a dishwasher, or to ask a non-Jew to sweep the floor knowing that the non-Jew will use a vacuum cleaner or will mop the floor with water. The reason is because the Jew simply wants the dishes to be cleaned, hence the Jew does not want, nor gains no additional benefit whether they are cleaned by hand or via a dishwasher. In other words, so long as it is possible for the non-Jew to do the activity in a permissible manner, even if the non-Jew decides to do it in a way that is prohibited on Shabbat (presumably because it is easier and quicker), it is not a problem of Amira L'akum.

* These laws were adapted from The Weekly Halacha, by R. Daniel Neustadt, and Sefer Shemirat Shabbat K'Hilcheta chap. 30-31. For any questions on the matter, please see Rav Friedman, as these are merely a sampling of the many complex laws that govern this issue.