Moed Katan, Chapter Two, Mishnah Four
This mishnah deals with two subjects: 1) buying large items on the festival; 2) using the festival as time to move ones belongings.
1) They may not purchase houses, slaves or cattle unless it is for the needs of the festival, or the need of the seller who does not have enough to eat.
2) They may not move [belongings] from one house to another house, but he may move [his belongings] within his courtyard.
3) They may not bring back vessels from the house of the craftsman, but if one is anxious about them, he may remove them to another courtyard.
Section one: It is forbidden to make large purchases on the festival, because the festival should not be used as a time to engage in activities needed for after the festival. There are, however, two circumstances, that allow one to make a large purchase on the festival. First of all, if the sale is necessary to the buyer for the needs of the festival. For instance, if ones house burned down right before the festival, he may buy a new one during the festival. The second circumstance is if the seller needs the cash immediately to buy food for the holiday. The general prohibition of buying and selling large items on the festival is waved if the seller needs money immediately in order to buy food in order to celebrate the festival itself.
Section two: Moving from one house to another is obviously a difficult and laborious endeavor. Since it involves so much work, one may not do so on the festival. However, he is allowed to move his stuff out to the adjacent courtyard because this is not nearly as strenuous. The Talmud explains that he can move from one house to another house within the same courtyard.
Section three: If one has left his vessels (clothes, utensils, cloth etc.) at a craftsman for repair, he cannot bring them home on the festival. According to the Talmud, this refers to vessels which are not needed on the festival. However, if he fears that someone might steal them from the craftsmans workshop, he may move them to a better-guarded workshop. While this may be just as much work as moving them to his own home, he is not allowed to bring them home lest someone plan ahead of time to use the festival as a opportunity to bring his things home from the craftsman.