عید قربان مبارک

The word "Eid" means a recurring festival. The name of Eid al-Adha means the Feast of Sacrifice. It is celebrated on the tenth day of the lunar month of Dhul-Hijjah.
  
On the ninth day of Dhul-Hijjah, pilgrims proceed to the plains of the Mount of `Arafah, outside Makkah and they spend their time totally in worship. This is the core of the worship of Hajj, without which no Hajj is said to have been performed. On that evening, pilgrims proceed from Arafah to Muzdalifah.

Early in the morning of the 10th day of Dhul-Hijjah, the pilgrims having offered their prayers at Muzdalifah, proceed to the three pillars to cast seven stones at the symbols of Satan. This ceremony of casting stones has been performed since the days of Prophet Ibrahim (Abraham) (peace be upon him).

It is a ceremony which indicates that one should cast away the evil of Satan repeatedly and resolve never to listen to him again, nor to succumb to temptations. In fact, the word for the casting process in Arabic is "rajm", which means throwing of stones.

Then, pilgrims return to Mina, with a pure slate of mind and heart, where they perform the sacrifice of animals. This process commemorates the event when Prophet Ibrahim was about to sacrifice his most beloved treasure, his son…

It was his only son, whom he begot in old age after sincerely having implored Allah, for a son for a very long time. It was Ismail--his beloved and righteous son--who was destined also to become a prophet. He is known as "Adh-dhabih", or the chosen sacrifice of Allah.

http://www.onislam.net