Bava Metzia, Chapter 2, Mishnah 8. In the previous mishnah, we learned how to calculate the net amount that the finder returns to the owner of the lost object, and to weigh accordingly how long he must keep the item and what expenses accrue in safeguarding it. The basis for this is in the verse: "Vehayah imcha ad drosh achicha oto vehasheivoto lo" - the finder must keep the lost item until his brother comes and demands it, and then he shall return it to him. The Gemara points out that the words "and then he shall return it to him" are seemingly superfluous, since it is obvious from the context that returning it is an automatic obligation; from here it is derived that one must calculate exactly what is returned to the owner.
The previous mishnah dealt only with considering costs and expenses. Our mishnah also deals with questions of quality: an item that sits for a long time might rot, rust, or be damaged in some other way. The guardian must take this into account, so that the item is returned to its owner in good condition.
"Matza sefarim - korei bahen achat lishloshim yom":
"Matza sefarim" - if he found books. The term "sefarim" in modern Hebrew denotes bound books, but in the time of the Mishnah they were all scrolls, like a Torah scroll. The scroll is made of organic material - parchment - and therefore can develop mold if it is not aired out occasionally. Therefore, "korei bahen achat lishloshim yom" - he reads them once every thirty days, and there is a dispute as to whether he must go through the entire book each time. "Ve'im eino yodea likrot - goleilan" - and if he does not know how to read, he rolls them: someone who does not know how to read rolls the scroll, since exposure to fresh air prevents the formation of mold.
The novel point is that since rolling is permitted anyway, reading while rolling is also permitted, as there is no damage in doing so. However, the mishnah qualifies this: "Aval lo yilmod bahen batchilah" - but he may not study them for the first time. The permission applies specifically to someone who has already studied the book in the past, and his current study is merely a quick review. But someone studying it for the first time will linger on the text for a long time in order to understand it, and this lingering is liable to wear out the scroll and damage it.
"Velo yikra acher imo" - and another person may not read with him. One may not allow another person to read it at the same time, out of concern that the two of them will each pull the scroll toward themselves and it will tear.
"Matza kesut - mena'arah achat lishloshim yom":
"Matza kesut" - if he found a garment, then he "mena'arah achat lishloshim yom" - shakes it out once every thirty days to air it out. According to the conclusion of the Gemara, for a woolen garment thirty days is an appropriate period for airing it out, whereas a linen garment should not be shaken out at all, since shaking damages it. The principle is to protect the garment from being ruined. Today, in dry and air-conditioned homes that have no mold, this may not apply to the same degree, and it is often best to leave the garment on a shelf or in a box.
"Veshotchah letzorkah, aval lo lichvodo" - and he spreads it out for its needs, but not for his honor. The finder is allowed to spread the garment out so it gets fresh air for its own sake, but not for the sake of his own honor: it was customary for people to show off their wealth by hanging many garments and carpets on the walls, and this one may not do. The Gemara raises a question: what is the rule when both conditions exist at once - the thirtieth day arrives, and at that very time guests are visiting his home, so spreading it out benefits both the garment and his honor? This question is left unresolved.
"Klei chesef vechlei nechoshet":
"Nechoshet" (copper) also includes brass and bronze, which are copper alloys with other metals. The Gemara explains that the responsible way to safeguard these vessels in the time of the Mishnah was by burying them in the ground, the safest place to hide objects. However, if left there permanently they would oxidize and corrode, and therefore they should not be left buried all the time. "Mishtamesh bahen letzorkan" - he uses them for their own needs. He should use them from time to time, with any use that benefits the vessels themselves so they do not corrode. "Aval lo leshachakan" - but not to wear them out. He should not use them so much that they are worn down, whether by leaving things inside them for too long or by using them too frequently, which wears away the silver or the copper.
"Klei zahav vechlei zechuchit":
These vessels do not rust: glass and gold can sit in their place for a long time. Furthermore, they are delicate - glass is easily broken, and gold is very thin. Therefore, "lo yiga bahen ad sheyavo Eliyahu" - he should not touch them until Eliyahu comes, as the finder has no reason to use them, since doing so brings no benefit to the owner of the lost item, but only personal enjoyment.
"Matza sak o kupah - vechol davar she'ein darko litol" - if he found a sack or a basket, or any item that is not his usual practice to take:
The language of the Mishnah can be misleading: it does not mean specifically a sack and a basket, but rather the principle learned from them - "vechol davar she'ein darko litol" - any item that is not his usual practice to take, meaning any object that the finder would not usually carry. That is to say, if his own basket or sack were sitting in the center of the city, he would not walk around with them. In such a case, "harei zeh lo yitol" - he shall not take it, meaning he is exempt from picking up the lost object. The basis for this law is in the verse "ve'hitalamta meihem" (and you shall hide yourself from them), which can be understood as permission to act as if he does not see, and to occasionally hide himself from the lost object.
The standard is the dignity of the finder: a person of standing, whose usual practice is not to carry objects of this sort. This can be compared to a person walking in the market for his shopping who sees army boots lying at the entrance to a store, with a note on them: "These belong to so-and-so, please return them to their owner." If he asks himself - if these were my shoes, would I walk through the city with army boots in my hands? - and the answer is negative, since he finds it embarrassing and would rather declare them ownerless and buy new ones, then just as he would not act this way with his own property, he is not obligated to act this way with his friend's property. He is permitted to leave the shoes, the bag, or the sack in their place, anything that is beneath his dignity, and leave it for someone else to take care of, and he is exempt.
In summary: Our Mishnah teaches that returning a lost object does not amount to passive guarding, but rather requires care adapted to the nature of each object: books - reading or rolling once every thirty days, provided he does not study a new topic in them and another person does not read along with him; clothing - shaking out once every thirty days, and spreading it out for its own need and not for his own honor; silver and copper vessels - using them for their own need but not to wear them out; gold and glass vessels - he may not touch them at all. Conversely, regarding an item that is not his usual practice to take, the finder is exempt from picking it up in the first place.