Midrash sobre Números 6:9

(Bamidbar 6:9) "And if one die on him, etc.": to exclude a doubt (i.e., a possibility of one's having died on him.) For it would follow (otherwise), viz.: If (in the instance of sotah) where inadvertency was not equated with wilfullness (viz. (Bamidbar 5:13), doubt (i.e., the possibility of her having been adulterous while closeted) was equated with certainty, then here, (in the instance of the Nazirite), where inadvertency was equated with wilfullness, how much more so should doubt be equated with certainty! It is, therefore, written "And if one died on him" (i.e., to his certain knowledge) — to exclude an instance of doubt. "of an instant": to include (his shaving and bringing an offering) (if he becomes tamei) inadvertently. For it would follow (otherwise), viz.: If (in the instance of sotah), where doubt was equated with certainty, inadvertency was not equated with wilfullness, then here, (in the instance of the Nazirite), where doubt was not equated with certainty, how much more so should inadvertency not be equated with wilfullness! It is, therefore, written "of an instant" (i.e., inadvertently). "suddenly": to include (an instance of his becoming tamei) unwittingly. For it would follow (otherwise), viz.: If, (in the instance of sotah), where doubt is equated with certainty, unwittingness (of his being forbidden to her) is not equated with wittingness, here, (in the instance of the Nazirite), where doubt (of his having become tamei) is not equated with certainty, how much more so should unwittingness (of his having become tamei) not be equated with wittingness! And whence is it derived that he is liable (to shave and bring an offering) for wilfullness (i.e., for wilfully having become tamei)? — Do you ask? It follows a fortiori, viz.: If in the instance of swearing (falsely) in respect to (having received) a pledge (viz. Vayikra 5:22), where he is not liable (to bring an offering) for unwittingness, he is liable for wilfullness, then here (in the instance of the Nazirite), where he is liable for unwittingness, how much more so is he liable for wilfullness! — No, this may be true of swearing in respect to a pledge, where he does not receive stripes, as opposed to the instance of the Nazirite, where he does receive stripes. And since he receives stripes, he should not bring an offering. It is, therefore, written (Bamidbar 6:11) "and he (the Cohein) shall atone for him for having sinned against the soul." These are the words of R. Yoshiyah. R. Yonathan says "of an instant": This refers to unwittingness. "suddenly": This refers to inadvertency.