The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj)

Dawud :: Book 10 : Hadith 1855

Narrated Ka'b ibn Ujrah:

A man from the Ansar said on the authority of Ka'b ibn Ujrah that he was feeling pain in his head (due to lice); so he shaved his head. The Prophet (peace_be_upon_him) ordered him to sacrifice a cow as offering.