Khuddakavatthukkhandhaka

Vinayapiṭaka · Cūḷavagga (2) · Vol. 7 · Section 151

[151] Now at that time a certain bhikkhu had a sore in the private parts (sambādha). The medicine would not stay on. … They reported this matter to the Blessed One. He said: "Bhikkhus, I allow, on account of illness, the hair in the private parts to be removed."

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 1 other place

Vol. 7 · Section 133 — Khuddakavatthukkhandhaka