مختصر صحيح بخاري
Mukhtasar Sahih Bukhari
What to do if prevented from Umrah
Narrated Ibn Abbas (may Allah be pleased with them) that the Messenger of Allah (peace and blessings of Allah be upon him) was prevented from entering Makkah and performing Umrah (in the year of Hudaybiyyah), so he shaved his head (there in Hudaybiyyah), had relations with his wives, and slaughtered the sacrificial animals. Then, in the following year, he performed the Umrah as compensation for that.
Being prevented from Hajj
It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that he used to say: "Is the Sunnah of the Messenger of Allah (peace and blessings be upon him) not sufficient for you? If any of you is prevented from performing Hajj, he should perform Tawaf of the Ka'bah and of Safa and Marwah, then come out of all the restrictions of Ihram, until he performs Hajj the following year and offers a sacrifice. And if he cannot find a sacrificial animal, then he should fast." (Also read the ahadith of these chapters: Book: On the Explanation of Hajj... Chapter: The one who takes a sacrificial animal with him..., Book: On the Explanation of Umrah... Chapter: How many Umrahs did the Noble Prophet (peace and blessings be upon him) perform?)
If prevented from Hajj or Umrah, sacrifice first then shave head
Narrated from Sayyiduna Miswar (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) offered the sacrifice before shaving his head (in the year when he was prevented from performing ‘Umrah), and he also commanded his companions to do the same.
Allah's command: "Charity" means feeding six needy persons
Sayyiduna Ka'b bin 'Ujrah (may Allah be pleased with him) says that during Hudaybiyyah, the Messenger of Allah (peace and blessings be upon him) was standing by me and lice were falling from my head. The Prophet (peace and blessings be upon him) said: "Are the lice troubling you?" I replied, "Yes." So the Prophet (peace and blessings be upon him) said: "Shave your head." (Ka'b, may Allah be pleased with him, says:) It was concerning me that this verse was revealed: "And whoever among you is ill or has an ailment of the head (necessitating shaving), then..." (__QUR_N__ al-Baqarah: 196). So the Noble Prophet (peace and blessings be upon him) said: "Fast three days, or feed six needy people, or offer whatever sacrifice is available."
In expiation, feed half a sa' of food
`Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) says in another narration that this verse was revealed specifically concerning me, and it is general for all of you.