The Holy Prophet SAW has said:
"One fast during the ten days of Zulhijjah is equal to the fasting of one complete year, and the worship of one night during this period is equal to the worship in Lailatul-Qadr." (Tirmidhi, Ibn Majah)
According to the rules set out by the Muhadditheen, this Hadith could be used for encouragement and virtues.
The month of Zulhijjah is the last month of the Islamic calendar. Literally it mean "the month of Hajj." Obviously this name of the month indicates that the great annual worship of "Hajj" is performed in this month. for this reason it has a peculiar significance as compared to other months of the year.
The first ten days of Zulhijjah are among the most magnificent days in the Islamic calendar.
The 9th day of Zulhijjah is called Yaum-ul-Arafah (The Day of Arafah). This is the date when the Hujjaj (Haji pilgrims, plural of Haajj) assemble on the plain of Arafat, six miles away from Makkah, where they perform the most essential part of the prescribed duties of hajj, namely, the Wuquf of Arafah.
For those not performing hajj, it is desirable to fast on this day. This fast has been greatly emphasised by the Holy Prophet SAW. According to one hadith, the fast of this day becomes a cause of forgiveness for sins committed in one year, InshaAllah.
Allah mentions in the Qur'an:
"...And by the ten days..." (Surah Al-Fajr)
The Ulama have explained that the above ten days mentioned in the ayat refer to the first ten days of Zulhijjah. Allah mentioned it and swore by it because of its great virtues.
This is further strengthen by the hadith whereby Rasulullah SAW announced:
"There is no other days in which ibadah is more loved by Allah then these ten days (that is, of the month of Zulhijjah)."
The Companions (RA) asked him (SAW):
"O Rasulullah! Even better than jihad in the cause of Allah?"
The Prophet SAW replied:
"Yes, it is even better than jihad in the cause of Allah, except if one goes out for jihad with his life and his wealth, and he do not return with both (i.e. is made shahid)."