In this lesson we will learn the third Mishnah in chapter three of Maseches Moed Katan, which lists the documents and legal instruments that may be written on Chol HaMoed. As we will see, the guiding reason in most cases is the concern of davar ha'aved - a loss that may result if the writing is postponed until after the festival.
The words of the Mishnah: "V'eilu kosvin bamoed" - and these may be written on the festival:
"Kidushei nashim" - one of the ways to betroth a woman is by writing a document and betrothing her through it, a method that is not practiced today; also included are the other betrothal documents brought in halachah. The reason for the permission is the concern that another man may precede him - that she might in the meantime become betrothed to someone else, and therefore one must act quickly and make certain that she becomes his wife.
"Gittin" - divorce documents, for example in the case of a husband who is about to set out on a long journey, for if the get is not written now his wife may be left an agunah.
"Shovrin" - receipts. If a person demands that his debt be repaid to him, and the debtor is unwilling to pay unless he receives a receipt in hand, one may write him a receipt on the festival.
"Deyaseki" - a document drawn up for a person on his deathbed who wishes to leave behind instructions in monetary matters.
"Matanah" - a document attesting that a certain object was given as a gift, and the reason is the concern that the giver may retract and change his mind.
"Prozbulin" - at the end of the Shemittah year a loan is cancelled, unless a prozbul was written for it. In order to prevent the loss of the loan a person needs to write a prozbul, and if the only opportunity he had to write it was on Chol HaMoed, it is permitted.
"Igros shum" - documents that beis din writes on behalf of the lender, stating that beis din appraised the borrower's property and ruled that the property be given to the lender as payment for the loan that he owes him.
"Igros mazon" - according to one explanation, documents that beis din writes concerning the sale of a person's property, from whose estate payment must be made to support his wife and daughters. According to another explanation, this refers to a document that a man signs undertaking to support the daughter of his new wife who was born to her from another husband.
Documents of beis din and official documents:
"Shtarei chalitzah" - a document confirming that chalitzah was performed.
"Mi'un" - a document verifying that a girl underwent the process of mi'un (refusal). This refers to an orphan who was married off by her mother or her brothers, whose betrothal is only rabbinic, and she is entitled to refuse the betrothal at a later stage; a document of mi'un is then written for her, verifying that she refused the marriage.
"Shtarei berurin" - a document recording the selection of the judges for a particular case: one side chooses one judge, the other side chooses the second, and the two judges themselves choose a third. The document verifying that decision is called a shtar berurin.
"Gezeiros beis din" - decrees that beis din enacts, which need to be publicized during Chol HaMoed.
"Igros shel reshus" - letters of authority:
According to Rashi, this refers to letters and orders written on behalf of the government.
Some understand that this refers to letters appointing judges.
And some understand that this refers to casual writing in general - writing that is not official, and is therefore considered the act of a layman rather than a craftsman's work, and for that reason it is permitted on Chol HaMoed.
In summary: in this Mishnah we listed the documents that may be written on Chol HaMoed - documents of betrothal and divorce, receipts, deathbed instructions, gift documents and a prozbul, appraisal documents and support documents, documents of chalitzah and mi'un, documents recording the selection of judges, decrees of beis din and letters of authority. What most of them have in common is the concern of davar ha'aved, and in the last of them, the fact that the writing is the act of a layman, which is not forbidden on the festival.