Ka'b b. Ujra (Allah be pleased with him) reported that the Messenger of Allah (ﷺ) happened to pass by him during the period of Hudaibiya. Thereupon he (the Holy Prophet) said to him (Ka'b b. Ujra):Do these vermins trouble your head? He said: Yes. Thereupon he (the Holy Prophet) said: Shave your head. Then sacrifice a goat or observe fasts for three days or give three sits of dates to feed six needy persons

English translation · Sahih Muslim