Eid-Al-Adha is one of the major holidays of Islam. 'Id Al-Adha or Eid al-Adha (Arabic عيدالأضحى, "Festival of the Sacrifice") is a major Islamic festival that takes place at the end of the Hajj (annual pilgrimage to Mecca). It is also known as 'Id al-Qurban or al-'Id al-Kabir (Major Festival).
When and why Muslims do to celebrate this Holiday?
The Festival takes place on the tenth day of the Islamic month Dhul-Hijjah, the last month of the Islamic calendar in which millions of Muslims from around the world make an annual pilgrimage to Macca in order to worship Allah and to honor the willingness of the Prophet Abraham (peace be upon him) to sacrifice his son Ishmael in response to a command from Allah. Satisfied with Abraham's devotion, Allah replaced Ishmael with a sheep at the last second, and the sheep was slaughtered instead. While pilgrims in Makkah re-enact this scene by slaughtering sheep of their own, Muslims who can afford it in the rest of the world also participate in this rite by slaughtering sheep, camels and cows.
The Qur'an describes Abraham as follows:
"Surely Abraham was an example, obedient to Allah, by nature upright, and he was not of the polytheists. He was grateful for Our bounties. We chose him and guided him unto a right path. We gave him good in this world, and in the next he will most surely be among the righteous." (Qur'an 16:120-121)
Eid al-Adha Observances:
Engage in takbir (saying Allahu-Akbar, Allahu-Akbar. La ila-ha ill-lal-lah. Allahu-Akbar, Allahu-Akbar. Wa-lilahill hamd. (Allah is great, Allah is great. There is no god but Allah. Allah is great, Allah is great. And all praises are for Allah) from after the Fajr prayer until the imam comes out for prayers.
Muslims around the world attend prayers. Prayers are followed by visits with family and friends, and the exchange of greetings and gifts. At some point, members of the family will visit a local farm or otherwise will make arrangements for the slaughter of an animal. The sacrifice is called Qurban. During the sacrifice, the following prayer is recited too:
It is recommended to go early to the prayer place. Offer the Eid prayers in congregation in an open place.
In the name of Allah
And Allah is the greatest
O Allah, indeed this is from you and for you
O Allah accept it from me.
The meat is distributed during the days of the holiday or shortly thereafter. One third of the meat is distributed to the poor, one third to neighbors and relatives while one third is kept by the person who offered the sacrifice for use within his or her own family.
Ref. Encyclopædia Britannica, Huda, Wikipedia