The Prophet passed by him while he was at Al-Hudaibiyah, before entering Makkah, and he was a Muhrim. He had lit a fire under a cooking pot and lice were falling all over his face. So he (the Prophet) said: "Have these lice of yours troubled you?" He said: "Yes." He said: "Shave and feed six of the poor with a Faraq" and a Faraq is three Sa - "or fast three days, or slaughter a sacrifice." Ibn Abi Najih (one of the narrators) said: "Or slaughter a sheep."
Jami` at-Tirmidhi Book 9, Hadith 147