from Ka'b bin 'Ujrah who said: "The Messenger of Allah (ﷺ) came to me while I was lighting a fire under a pot, and lice were falling on my face, or on my eye-brows. He said: 'Are your lice bothering you?'" "I said: 'Yes.' He said: 'Then shave your head and offer a sacrifice, or fast three days, or feed six needy people.'" Ayyub said: "I do not know which of them he started with."
Jami` at-Tirmidhi Book 47, Hadith 26
← Previous Hadith that Ka'b bin 'Ujrah said: "By the one in Whose Hand is my soul! This Ayah was revealed referring to my case: 'And whosoever of you is ill or has an ailment on his scalp (necessitating shaving) he must pay Fidyah of either fasting or giving charity, or a sacrifice. (2:196)'"

He said: "We were with the Messenger of Allah (ﷺ) at Al-Hudaibiyyah and we were in a state of Ihram. The idolaters had held us back, and I had a good deal of hair, and the lice were falling on my face. The Prophet (ﷺ) passed by me and said: 'The lice on your head are bothering you?'" He said: "I said: 'Yes.' He said: 'Then shave.' And this Ayah was revealed."

Mujahid said: "The fasting is for three days, the feeding is six needy people, and the sacrifice is a sheep or more."

Jami` at-Tirmidhi Book 47, Hadith 25 Next Hadith → that the Messenger of Allah (ﷺ) said: "The Hajj is 'Arafat, the Hajj is 'Arafat, the Hajj is 'Arafat. The days of Mina are three: But whoever hastens to leave in two days, there is no sin on him, and whoever stays on, there is no sin on him (2:203). And whoever sees (attends) the 'Arafah before the rising of Fajr, then he has performed the Hajj." Ibn Abi 'Umar said: "Sufyan bin 'Uyainah said: 'This is the best Hadith that Ath-Thawri reported.'"

Jami` at-Tirmidhi Book 47, Hadith 27