OPINIONS: The Mishnah states that one who is traveling on Friday when the sun begins to set should give his wallet to a Nochri in order not to transgress the Melachah of carrying an object in Reshus ha'Rabim on Shabbos. When exactly should he give his wallet to the Nochri?

(a) RASHI (DH Mi she'Hechshich) says that he must give the wallet to the Nochri while it is still day, before Shabbos enters.

(b) The ROSH says that one may give his wallet to the Nochri after Shabbos enters. This is evident from the Gemara which asks why one is permitted to give his wallet to a Nochri. According to Rashi's explanation, there is no reason why one should not be permitted to give his wallet to the Nochri, since he gives it to the Nochri before Shabbos!

The Rosh suggests two additional proofs from the Gemara that Rashi's explanation is not correct. First, the Gemara says that this Halachah applies only to one's wallet (or any other object that he owns), but not to an object that he finds, since he has not yet acquired ownership of that object. If the Mishnah refers to the time before Shabbos enters, then the person should simply acquire the object before Shabbos by lifting it, and the Gemara's discussion of an object which he found is not relevant. Second, when the Gemara says that if there is no Nochri available, one may place his wallet on his donkey, the Gemara rejoins that if one places his wallet on his donkey, he transgresses the Melachah of Mechamer. The Mishnah must be referring to after Shabbos has already entered, because before Shabbos enters one does not do the Melachah of Mechamer when he places his wallet on the donkey.

The BACH and the KORBAN NESANEL explain that Rashi's intention is to say what one must do l'Chatchilah -- he must give his wallet to a Nochri before Shabbos enters. However, b'Di'eved, if he did not give his wallet to a Nochri until after nightfall, he may still give his wallet to a Nochri to watch and he does not have to abandon it there.

The Bach explains that the reason why Rashi understands that the Mishnah is teaching what one should do l'Chatchilah is because the Mishnah says, "If it became dark while one was traveling, he should give his wallet to a Nochri." This implies that the Mishnah is instructing what one should do to avoid a transgression (such as carrying on Shabbos, or holding Muktzah). If the Mishnah means to teach what one should do when Shabbos has already entered, then it should say, "If it became dark while one was traveling, one is permitted to give his wallet to a Nochri," and thereby teach what one may or may not do on Shabbos.