Khuddakavatthukkhandhaka

Vinayapiṭaka · Cūḷavagga (2) · Vol. 7 · Section 153

[153] Now at that time a certain bhikkhu had a sore on his head. He was not able to have his hair removed with a razor. They reported this matter to the Blessed One. He said: "Bhikkhus, I allow, on account of illness, hair to be cut with scissors."

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.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