If a caterer runs out of drinks at a shabbos kiddish and feels that people will be upset at him and the caterer also feels that his reputation will become negative after the kiddish etc.; can the caterer instruct a gentile to purchase drinks at the local store on shabbos. Do we say Shvus (amira to gentile) D’shvus (purchasing soda) bemakom mitzva (of shabbos kiddish) or potential hefsed of future business in this case?
It is permitted to perform a shevus de-shevus for the purpose of a mitzvah, as ruled by the Rema (Orach Chaim 276:2). A classic example for this is for the purposes of the Shabbos Se’udah (Mishnah Berurah 325:60).
However, the Mishnah Berurah (62) writes that this does not apply for “extras” in the meal.
The question here is whether or not the drinks will be considered an “extra” or not. Because drinks are basic to a kiddush, there is certainly room to argue that this is a “basic,” and room to be lenient.
The concern for parnassah is also significant, as we find in the Shulchan Aruch. For a shevus de-shevus, there is room for leniency even where the loss is not so great, though it has to be significant. See Shulchan Aruch 307:5.
In this case, it appears that the potential loss is significant, and therefore there will be room to permit asking a non-Jew to buy the drinks.