Al-Baqarah 2:196

Narrated Abu Musa:The Prophet (ﷺ) sent me to some people in Yemen and when I returned, I found him at Al-Batha. He asked me, "With what intention have you assumed Ihram (i.e. for Hajj or for Umra or for both?") I replied, "I have assumed Ihram with an intention like that of the Prophet." He asked, "Have you a Hadi with you?" I replied in the negative. He ordered me to perform Tawaf round the Ka`ba and between Safa and Marwa and then to finish my Ihram. I did so and went to a woman from my tribe who combed my hair or washed my head. Then, when `Umar came (i.e. became Caliph) he said, "If we follow Allah's Book, it orders us to complete Hajj and Umra; as Allah says: "Perform the Hajj and Umra…

Narrated Ka`b bin `Umra:Allah's Messenger (ﷺ) stood beside me at Al-Hudaibiya and the lice were falling from my head in great number. He asked me, "Have your lice troubled you?" I replied in the affirmative. He ordered me to get my head shaved. Ka`b added, "This Holy Verse:--'And if any of you is ill, or has ailment in his scalp (2.196), etc. was revealed regarding me. "The Prophet (ﷺ) then ordered me either to fast three days, or to feed six poor persons with one Faraq (three Sas) (of dates), or to slaughter a sheep, etc. (sacrifice) whatever was available

Narrated `Abdullah bin Ma`qil:I sat with Ka`b bin Ujra in this mosque, i.e. Kufa Mosque, and asked him about the meaning of: "Pay a ransom (i.e. Fidya) of either fasting or . . . . (2.196)" He said, "I was taken to the Prophet (ﷺ) while lice were falling on my face. The Prophet (ﷺ) said, 'I did not think that your trouble reached to such an extent. Can you afford to slaughter a sheep (as a ransom for shaving your head)?' I said, 'No.' He said, 'Then fast for three days, or feed six poor persons by giving half a Sa of food for each and shave your head.' So the above Verse was revealed especially for me and generally for all of you

Narrated Mujahid: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…