Midrash su Numeri 6:5

4) "his head": Why is this written? (i.e., Why is the above generalization not sufficient to include it?) Because it is written (of a Nazirite, Bamidbar 6:5) "a blade shall not pass over his head, I might think (that this includes) even a leprous (Nazirite); it is, therefore, written "his head." "his beard": Why is this written? Because it is written (of Cohanim, Vayikra 21:5): "the corner of their beard they shall not shave off," I might think (that this includes) even a leprous (Cohein); it is, therefore, written "his beard." Why mention both "his head" and "his beard"? (i.e., Why can one not be derived from the other?) — Because there obtain (strictures) with head which do not obtain with beard, and with beard, which do not obtain with head — The head (of a Nazirite) is forbidden both with scissors and with blade, and the (destruction of the) beard does not obtain with scissors; the head is permitted with all men (who are not Nazirites), and the (destruction of the beard is forbidden with all men — Because there obtain with head (strictures) which do not obtain with beard, and with beard (strictures) which do not obtain with head, there must be written (to include for the shaving of the leper) both "his head" and "his beard."

6) "Then he shall be shaved": even if he is a Nazirite. Because it is written (of a Nazirite, Bamidbar 6:5) "a razor shall not pass over his head," I might think even if he was afflicted (with leprosy); it is, therefore, written "Then he shall be shaved" — even if he was afflicted.

Similarly, Absalom was punished by the very thing with which he prided himself, as it is said: Now in all Israel there was none to be so much praised as Absalom for his beauty; from the soul of his feet to the crown of his head there was no blemish in him … and when he polled his head … now it was every year’s end that he polled it (II Sam. 14:25–26). R. Nehorai stated: He was a Nazirite, yet he cut his hair every thirty days,¹⁰Nazirites are forbidden to cut their hair (Num. 6:5). as it is said: Now at the end of the days he polled it. R. Judah maintained that he was a Nazirite throughout his life, yet he cut his hair every twelve months, as it is said: And it came to pass at the end of forty years that Absalom said unto the king: “I pray thee, let me go and pay my vow, which I have vowed unto the Lord in Hebron. For thy servant vowed a vow while I abode at Geshur in Aram, saying: If the Lord shall indeed bring me back to Jerusalem, then I will serve the Lord” (II Sam. 15:7–8).