Nedarim 3 - Do not delay
On the previous page we were left with the question, why the teacher sometimes chooses to explain the concepts out of order, while sometimes he does explain them in the order of introduction. The answer is that the teacher loves complicated and non-obvious derivations, and prefers to explain them first.
Just as one can vow not to eat, drink, or use an object, so one can vow to become a Nazir, so that he won't drink wine, cut his hair or go to a cemetery. The laws of vows and of Nazir are parallel: one should not violate his vow nor should he delay it.
However, how can one violate a "do not delay" to become a Nazir? All the time that he is not a Nazir, he is not, and there is no requirement to become one. And once he vows to be a Nazir, he is, and he is not delaying anything.
This situation can be found when he says, "I will be a Nazir before I die." Since he does not know when he will die, he should become a Nazir immediately, because he might die the next moment. All the time that he does not become a Nazir, he violates the "do not delay" prohibition. This is similar to the one who says to his wife, "Here is your divorce (Get) an instant before I die." If for example she is married to a Kohen, she is immediately prohibited to eat the Kohen's portion (terumah) since he may die the very next moment, and it would come out that she ate terumah illegally.
Art: A seated Peasant eating a Meal by German School