633. Giving Work to a Non-Jew Before Shabbos
A Jew may not give utensils to a non-Jewish artisan to craft on Friday, even if the craftsman has a set price for the job, unless there is time to pick the articles up before Shabbos. Similarly, a Jew may not sell, lend, pawn, or make a gift of his property to a non-Jew unless the non-Jew can remove the item from the Jew's house before Shabbos. This is because as long as the non-Jew is in the Jew's house, no one knows when the Jew gave him the object. Therefore, if the non-Jew were to leave with the item on Shabbos, it would appear that the thing was being lent, pawned, handed over to be worked on, or sold on Shabbos.
Let’s say that a Jew gave a non-Jew a letter to deliver to another city. If there’s a set fee for this service, it is permitted even if the Jew gave him the letter on Friday afternoon, as long as the non-Jew leaves the Jew's house before Shabbos begins. If a fee was not set but there is a designated person in the city who collects letters and delivers them to other cities through his agents, then it is permitted to give the letter to a non-Jew as long as there is enough time for it to reach a house opposite the city wall before Shabbos begins, which is the farthest away that the home of the non-Jew who handles the mail delivery might be. If there is no designated mail official and the non-Jew to whom the Jew gives the letter is the one who will deliver it to the other city, then it is always prohibited to send a letter without fixing the price in advance.