Before us is Mishnah 5 in the first chapter of Maseches Nazir. The Mishnah deals with a person who said: "Hareini nazir k'melo ha'bayis" - "I am hereby a nazir like the fullness of the house," or "k'melo ha'kupah" - "like the fullness of the basket" - wording that expresses something enormously large, a measure that fills an entire house.
Bodkin oso:
The Mishnah establishes that beis din examines the one who took the vow and asks him what he meant by his statement. There are two possibilities before us:
He meant one very great nezirus: Then it is nothing more than a nezirus of thirty days. Such a statement is comparable to the statements explained in Mishnah 3: all those expressions of great periods of nezirus amount to no more than an ordinary nezirus. Even though in the mind of the speaker he is describing something long and great, there is no actual nezirus here that extends beyond thirty days.
He explained that he had no particular intention: Rather, he assumed that his statement would be interpreted for him by others. In this case we view the basket he mentioned as though it were filled with mustard seeds - tiny seeds whose number is enormous - and he is therefore a nazir for the rest of his life.
Dependence on the dispute in the previous Mishnah:
How "a nazir for the rest of his life" is understood depends on the dispute explained in the previous Mishnah:
According to the Tanna Kamma: He has upon himself many separate periods of nezirus, completing one nezirus and beginning another every thirty days.
According to Rabbi: It is one long nezirus that continues for the rest of his life.
In summary: This Mishnah teaches that when a person takes a vow using wording that expresses a large measure, beis din examines his intention: if he meant one great nezirus, it is nothing more than a nezirus of thirty days; and if he had no particular intention, his words are interpreted as a full basket of mustard seeds, and he is a nazir for the rest of his life - whether as many periods of nezirus one after another according to the Tanna Kamma, or as one long nezirus according to Rabbi.