The ninth day of Dhul-Hijjah is the Day of 'Arafah, since it is on this Day the pilgrims gather at the mountain plain of 'Arafah, praying and supplicating to their Lord. In fact, one hadith says that ‘Hajj is Arafah' (Abu Dawud). This means Arafah is the sum and substance of Hajj.
The day of Arafah is also significant because this amazing ayah was revealed on this day:
"This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion." (Surah al Maa'idah 5:3)
Arafah was the Day on which Allah perfected His religion, completed His favours upon His beloved Prophet Muhammad (pbuh), and approved Islam as a way of life!
Imam Ibn Kathir in his tafsir says:
"Imam Ahmad recorded that Tariq bin Shihab said, "A Jewish man said to `Umar bin Al-Khattab, `O Leader of the Believers! There is a verse in your Book, which is read by all of you (Muslims), and had it been revealed to us, we would have taken that day (on which it was revealed) as a day of celebration.' `Umar bin Al-Khattab asked, `Which is that verse?' The Jew replied:
"This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion."
Umar replied, "By Allah! I know when and where this verse was revealed to Allah's Messenger. It was the evening on the Day of `Arafah on a Friday."
The day of Arafah is also significant because Allah swore by this Day in Surah al Burooj. It is known that Allah swears by nothing except that which is great and mighty! So the Day of Arafah is great significant:
"By the sky containing great stars. And [by] the promised Day. And [by] the witness and what is witnessed" (85: 1-3)
It was reported from Abu Hurayrah (ra) that the Prophet (pbuh) said:
"The promised day is the Day of Resurrection, the witnessed day is the Day of ‘Arafaah, and the witnessing day is Friday." (Tirmidhi)
It is a recommended sunnah of the Prophet (pbuh) for those who are not pilgrims to fast on this day, since the Prophet (pbuh) was asked about fasting on the day of Arafah, so he said:
"It expiates the sins of the past year and the coming year." (Muslim)
The Prophet (pbuh) also said:
"There is no day on which Allaah frees people from the Fire more so than on the day of 'Arafah. He comes close to those (people standing on 'Arafah), and then He reveals before His Angels saying, ‘What are these people seeking." (Muslim)
