Before us is Mishnah 5 of chapter 5 of Maseches Shekalim, which deals with someone who lost his seal - the ticket in his hand, by means of which he is entitled to receive the libations.
The text of the Mishnah and its explanation:
"Mi she'avad mimenu chosamo" - one who lost his seal, the ticket he was holding.
"Mamtinin lo ad ha'erev" - they tell him to wait until the evening.
"Im matz'u lo k'neged chosamo - nosnin lo" - if a surplus of money is found in the amount that corresponds to his seal, they give him the money, since it matches the amount of his loss.
"Im lav - lo hayah lo" - and if they have no surplus, he receives nothing, and the loss is his own.
"V'shem hayom kasuv aleha mipnei haramain" - the name of the day was written on it because of the swindlers:
They would write the date on the seals, and this was because of the swindlers. What exactly was the fraud they sought to prevent? On this the commentators disagree:
First explanation: The concern is that a person will lose his seal, another will find it, and after a few days he will bring it and use it. The date prevents this, for once it is established that the seal must be used on that very day, and on that day the owner is going about searching for his lost item, the finder does not have the nerve to try to use it. But without the date, after a few days, when he assumes that the owner has already left, he would use it.
Second explanation: Were there no date on the seal, a person would use it many days later. On the first day he would claim that he had lost his seal, and if a surplus of money was found he would receive the surplus; and afterward he would produce that very same seal at a later time and use it to receive the libations.
In summary: In this Mishnah we learned the law of one who lost his seal - that they wait for him until the evening, and if a surplus is found corresponding to his seal they give it to him, and if not, the loss is his. We also learned about writing the name of the day on the seal because of the swindlers, and the two explanations given for this: preventing the use of a seal that was found days later, and preventing someone from taking the surplus and then using that same seal again at a later time.