Másgiách

One who leaves a non-Jew alone in his house, and inside there are things that could be switched, and they would be then forbidden by the Torah, if he goes out and [re-]enters or even if he waited a long time and did not inform him that he intends to wait, it is permitted, and we do not worry that perhaps he switched it, even if he will benefit from switching the product, and this is provided that he does not lock his house up. Because he is afraid the entire time, saying, “Now he will return and he will see me.” But if he informed that he intended to wait, it is forbidden. But if he will not benefit from the switch, it is permitted in any case, for we are not concerned that perhapse he will switch them and cause the owner to stumble, since he gains no benefit from this matter.

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