Megillah, Chapter 1, Mishnah 6. We continue with the theme of the previous mishnayos: distinguishing between two halachos that resemble one another, with only a narrow difference between them.
"Ein bein hamudar hana'ah meichaveiro l'mudar mimenu ma'achal ela derisas haregel v'keilim she'ein osin bahem ochel nefesh":
The Mishnah sets two people who made vows opposite one another:
One who vowed not to benefit from his fellow - a person who vowed that he would derive no benefit at all from his fellow, in any form of benefit.
One who vowed not to take food from him - a person who vowed only that he would not benefit from his fellow's food, and that is the sole benefit he does not receive from him.
Between these two types of vows there is no distinction, except in two matters alone:
"Derisas haregel" - the question of whether he may set foot on his fellow's property. This is not a food benefit but a general benefit, and therefore it is forbidden only to the one who vowed against all benefit, and permitted to the one who vowed only against food, since it has nothing to do with food.
"V'keilim she'ein osin bahem ochel nefesh" - utensils that are not used for preparing food. Utensils designated for food are forbidden even to one who vowed only against benefit from food; but utensils unrelated to food, which are the subject of our mishnah, are permitted to the one who vowed against food and forbidden to the one who vowed against all benefit.
The Gemara adds that in a place where it is customary to rent out utensils, such utensils would be forbidden even to one who vowed only against benefit from food. The reason: since one can receive cash for renting out the utensils, and that cash can be converted into food, it is considered a food benefit. Take a coat, for example: in a place where it is customary to rent out coats, one who vowed against food may not benefit from it, since the coat can lead to a food benefit by way of the cash received for renting it out.
"Ein bein nedarim l'nedavos":
This matter concerns a person who wishes to obligate himself to bring a korban to the Beis HaMikdash. Two paths lie before him:
Neder (a vow) - the person says: "I hereby take upon myself to bring a korban." Once he has accepted it upon himself, the responsibility rests on him to see the matter through and to make sure the korban is actually brought.
Nedavah (a free-will offering) - the person does not accept responsibility upon himself in advance; rather, he takes a particular animal, brings it to the Beis HaMikdash and says: "This animal is a korban." If the animal is still in existence, he brings it; if it is not, he bears no responsibility.
And this is the language of the Mishnah: "Ela shehanedarim chayav b'achrayusan u'nedavos eino chayav b'achrayusan". With a neder, if he consecrated an animal and it died, he is still obligated to bring another animal in its place. With a nedavah, in which he designated one particular animal as the korban, if that animal died he bears no further responsibility.
In summary: in this mishnah, the Mishnah takes up two pairs of similar halachos. In the first pair: one who vowed against all benefit from his fellow and one who vowed only against his food are alike in everything, and differ only regarding setting foot on his property and utensils that are not used for preparing food - provided that this is not a place where it is customary to rent out utensils, in which case those too fall under the category of a food benefit. In the second pair: nedarim and nedavos are alike in everything, and differ only regarding the obligation of responsibility - that with a neder he is responsible for the korban, and with a nedavah he is not.