Nazir 16B

קסבר רבי אליעזר: כל אחר מלאת שבעה ⁠— סותר. ״הריני נזיר שלשים יום״, ונטמא יום שלשים ⁠— סותר את הכל, לא פליג רבי אליעזר דאמר שלימין.

The Talmud explains: R' Eliezer holds that when anyone becomes ritually impure after the completion of his term of naziriteship, but before he brought his offerings, only 7 days are negated, and the 30th day is after the completion of his term. The Mishnah then teaches that one who said: I am hereby a nazirite for 30 days, and became impure on the 30th day, it negates the entire tally. R' Eliezer does not disagree in this case, since it is an instance where he explicitly said that he accepts naziriteship on himself for a full 30 days, and his ritual impurity therefore occurs during his naziriteship period.

״הריני נזיר מאה יום״, ונטמא יום מאה ⁠— סותר את הכל, רבי אליעזר אומר: אינו סותר אלא שלשים. וכולה כדהוינן בה אליבא דבר פדא ורב מתנא.

The Mishnah also taught that if one said: I am hereby a nazirite for 100 days, and he became impure on the one hundredth day, it negates the entire tally. R' Eliezer says it negates only 30. And this entire Mishnah should be explained as we discussed it, in accordance with the opinions of bar Padda and Rav Mattana earlier (5a–6b).

מתני׳ מי שנזר והוא בבית הקברות, אפילו היה שם שלשים יום ⁠— אין עולין לו מן המנין, ואינו מביא קרבן טומאה. יצא ונכנס ⁠— עולין לו מן המנין, ומביא קרבן טומאה.

Mishnah: One who took a vow of naziriteship while in a cemetery, even if he was there for a full 30 days without leaving, those days he spent in the cemetery do not count as part of his tally, since his naziriteship has not yet gone into effect. And he therefore does not bring the 3 offerings of impurity, brought by a nazirite when rendered ritually impure by contact with a corpse, despite having been in a cemetery. If he left the cemetery and entered it again, those days do count as part of his tally, meaning the naziriteship takes effect, and he does bring the offerings of impurity for reentering the cemetery.