[bm42a: We begin with the mishna at the top of the page. Although it is not explicitly stated, the mishna is dealing with an unpaid custodian. Later, the gemara will rule that a paid custodian has greater liability.]
Mishna: If one deposited money with his fellow and he (the custodian) bundled it up and slung it over his shoulder, or gave it to his young son or daughter and locked the door ineffectively [so that the children could get out and lose the money], he is liable because he did not guard the way that custodians normally do. But if he did guard the money the way custodians normally do, he is not liable.
Gemara: It [the custodian's liability] is understandable in all the other cases [in the mishna] because he did not guard it in the manner of custodians. But when he bundled it and slung it over his shoulder -- what else should he have done?
Rava said in the name of Rav Yitzchak: The verse [Deut 14:25, describing how money for the second tithe must be brought to Jerusalem] says "... and thou shalt tie up the money in thy hand." Even if it is tied up, it must be in your hand. [The verse implies that prudent bundling means keeping the bundle visible, not slinging it over one's shoulder.]
[The gemara will now cite several other statements by Rav Yitzchak.]
And Rav Yitzchak said: A person's money should always be "in his hand" [Rashi: readily available, and not deposited with someone else], as the verse says "And thou shalt tie up the money in your hand."
And Rav Yitzchak said: A person should always divide his money into thirds: a third in real estate, a third in merchandise, and a third readily available.
And Rav Yitzchak said: There is no blessing [Rashi: produce which increases in quantity by itself] except for something which is hidden from direct view, as it says [Deut 28:8] "The Lord will command the blessing with thee in thy barns." [This is a play on words, comparing the word "asam" {barn, more appropriately translated as a storage place for grain, i.e. a silo) with "samui: {hidden}.]
A b'raita was taught in the academy of R. Yishmael: There is no blessing except for something which the eye cannot see, as it says [Deut 28:8] "The Lord will command the blessing with thee in thy barns." [This is the same message as R. Yitzhak's. There is no play on words, but merely a suggestion that anything that has been stored is hidden from view.]
The rabbis taught in a b'raita: One prepares to measure the grain in his silo says the following prayer: May it be Your will, Our God, that you bless the work of our hands." When he starts to measure, he says "Blessed is He Who blesses this pile." If he measured and then said the blessing, the blessing is in vain, for a blessing is not found in anything that has beden weighed or measured or counted, but only in something which is hidden from the eye [i.e., no known quantity], as it is said "God will command the blessing with you in your barns."
Shmuel said: The only way to (adequately) guard money is in the ground [i.e., to bury it]. [The previous discussion indicated that carrying the money in one's hand was sufficient, based on the verse describing carrying ma'aser money to Jerusalem in one's hand. That level of care is sufficient if one is traveling. But if one is at home, the only way for the custodian to avoid any liability for theft would be to bury it.]
Rava said: Shmuel would concede that Erev Shabbat just before sunset, the rabbis did not require (burying the money). But if he waited until after Shabbat for the length of time it takes to bury the money but did not do so, he _is_ liable. But if he [the person depositing the money] is a young scholar, he (the custodian) is not liable; [we can assume] he thought that the owner might need the money for havdala [i.e., for buying wine for the Havadala service after Shabbat]. And nowadays that there are "probers" [Rashi: thieves who probe the ground with metal rods to discover hollow caches of buried valuables], there is no acceptable form of guarding except above the beams in the ceiling.
[The next bits of text were obviously later additions, as the thieves became more sophisticated.]
And nowadays when there are thieves that break ceilings, there is no acceptable form of guarding except between the bricks of walls. Rava said that Shmuel concedes [that it is acceptable to hide money] in the wall.
And nowadays that there are wall-tappers [Rashi: thieves who tap on the walls to discover hollow caches of valuables], there is no adequate guarding of money except [placed in a wall] within a tefach of the floor or ceiling [where the thieves were apparently less likely to find it].
Rav Acha b. Rav Yosef asked Rav Ashi: We learned [Pesachim 31b, discussing chametz on Pesach] that if a building collapsed on some chametz, it is as if the chametz has been removed [and the owner need not worry about destroying or otherwise getting rid of the chametz]. Rabban Shimon b. Gamliel said: provided [that the chametz is sufficiently deep] that a dog cannot search for it. How deeply does a dog search? Three tefachim. [One tefach is a hand's breadth: about 10 cm or 4 inches.]
[Rav Acha continued:] Here [in our case of burying money], do we require three tefachim or not?
He said to him [Rav Ashi to Rav Acha:] There [in the case of chametz] we require three tefachim because of the scent [that will attract the dog]; here we are hiding it [from thieves], and we do not require three tefachim.
How much [depth] do we require? Rafram of Sichra said one tefach.
There was a man who deposited money. (The custodian) put it in a hut made of willow branches [Rashi: A conical hut used as a blind by people hunting birds], and the money was stolen. Rav Yosef said: Even though this is an acceptable form of protecting from theft, it is not an acceptable form of protecting from fire. Thus, this is a case which started with negligence and ended in unavoidable loss, and (the custodian) is liable.
Others say that even though it was negligent with regard to fire, it is protection against thieves, and in a case that started with negligence and ended with unavoidable loss, he (the custodian) is not liable [because the unavoidable loss was not related to the negligence]. The halakhah is that if it began with negligence and ended with unavioidable loss [even if the loss is not directly related to the negligence], he is liable.
[Another case:] A man deposited money, and when he said "Give me my money," he (the custodian) said "I don't know where I put it." He came before Rava; Rava said "Any 'I don't know (where I put it)' is negligence -- go and pay."
A man deposited money, and he (the custodian) gave it to his (the custodian's) mother (for safekeeping). She put it in a chest, and it was stolen. Rava said: How shall the judges rule in this case? If we say (to the custodian) "Go and pay," he will claim that anyone who makes a deposit does so with the understanding that (he the custodian may transfer it to) his wife and older children [and, by extension, his mother too]. If we tell the mother to pay [since the only way to safeguard money is to bury it], she may claim that he didn't tell me that the money was not his; (had he done so) I would have buried it. If we ask the custodian why he did not tell (his mother that the money was not his), he can claim that he thought that she would take even better care of his money (than of someone else's). Rava ruled: He (the custodian) swears that he gave the money to his mother, and she swears that she put the money in a chest and it was stolen, and he not liable. [The custodian is not liable because depositors accept the possibility that the custodian will transfer care the money to close family members. And the mother is not liable because storage in a chest is an acceptable form of safeguarding money that she thought was her son's, on the grounds that he might need it soon.]
[We end on the 8th line of 42b.]