(1) بَابُ كَفَّارَاتِ الأَيْمَانِ
Narrated Ka`b bin 'Ujra:
I came to the Prophet (ﷺ) and he said to me, "Come near." So I went near to him and he said, "Are your lice troubling you?" I replied, "Yes." He said, "(Shave your head and) make expiation in the form of fasting, Sadaqa (giving in charity), or offering a sacrifice." (The sub-narrator) Aiyub said, "Fasting should be for three days, and the Nusuk (sacrifice) is to be a sheep, and the Sadaqa is to be given to six poor persons."
Reference: Sahih al-Bukhari 6708
In-book reference: Book 84, Hadith 1
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 79, Hadith 699