Muslims believe that it was during those Ten Days that Abraham the Bosom Friend-Ibrahim al-Khalil (peace be upon him) obtained the bosom friendship bestowed upon him by Allah, having sacrificed his wealth for the sake of the guests, himself for the sake of the fires, his son for the sake of the Criterion-Furqan, and his heart for the sake of the All-Merciful.
Dhul-Hijjah (the Month of Hajj) is the 12th month of the Islamic lunar year. It is during this month that the annual pilgrimage to Mecca, known as Hajj, takes place. The actual pilgrimage rites take place on the 8th to 12th days of the month.
According to the Prophet Muhammad, peace be upon him, the first ten days of this month are a special time for devotion. During these days, preparations are underway for those who are undertaking the pilgrimage, and most of the actual pilgrimage rites occur. In particular, the 9th day of the month marks the Day of Arafat, and the 10th day of the month marks the Eid al-Adha (Festival of Sacrifice). Even for those who are not travelling for the pilgrimage, this is a special time to remember Allah and spend extra time in devotion and good deeds.