In this lesson we will learn the first Mishnah of the twenty third chapter of Maseches Shabbos. The Mishnah rules that a person may ask his friend on Shabbos for jugs of wine and jugs of oil, provided that he does not use the expression "halveni" - that is, the language of a loan - but rather the expression "hash'ileni" (lend me as a borrowed item).
What, then, is the difference between "hash'ileni" and "halveni"?
The Gemara's explanation:
The Gemara explains that with the language of a loan there is a concern that the owner of the item will come to record the loan in his ledger, since a loan is a term that indicates a longer period of time, and out of concern that he may forget the matter he is liable to come to write it down on Shabbos.
The approach of Tosafos:
Tosafos understood that a borrowed item can also be for exactly the same period of time as a loan, and therefore they explained the difference in a different way:
She'elah (borrowing) - a term generally used for an item where the borrower returns the very object he received.
Halvaah (a loan) - a term used for something where one does not return the item itself, but rather pays its value in cash or the like.
According to this, even when a person borrows an item such as wine or oil, where one does not return that very same thing but a different item, the very use of the expression "hash'ileni" - the concept of borrowing - serves as a reminder not to write. But when he uses the language of a loan, which refers to something where the item itself is not returned, there is a concern that he will come to write.
The Mishnah continues: a woman too may ask her friend for loaves of bread, provided that she does not use the language of a loan.
Leaving a security deposit on Shabbos:
When borrowing food from a friend: A person who wishes to ask his friend on Shabbos for a type of food and the like, and his friend does not trust him, may tell him to leave his tallis there, and it will serve as security. After Shabbos they will settle the account of the debt for the item.
On Erev Pesach that falls on Shabbos in Yerushalayim: The law is the same. A person who needs a Korban Pesach may approach someone who sells lambs, leave his tallis with the seller, take a lamb from him for the Korban Pesach, and settle the account with him after Yom Tov for what he actually owes him.
In summary: In this Mishnah we learned that borrowing items on Shabbos is permitted using the expression "hash'ileni" and forbidden using the expression "halveni", out of concern that the owner of the item will come to write on Shabbos - whether because a loan indicates a longer period of time (as the Gemara explains), or because a loan by its nature refers to something where the item itself is not returned (as Tosafos hold). We also learned that the same law applies to borrowing loaves between women, and that one may leave security such as a tallis and settle the account after Shabbos - both when borrowing food from a friend, and when taking a lamb for the Korban Pesach on Erev Pesach that falls on Shabbos.