Fasting the day of Arafah 

The ninth day of Dhul-Hijja is the day of 'Arafah. It is the day during which Hajj pilgrims stand on the plain of Arafah to pray and supplicate. On this day, It is preferable (Mustahhib) for us to fast.

Abû Hafsah reported that the our beloved prophet Muhammad (peace and blessings of Allah be upon him) said:

"Fasting on the day of Arafah absolves the sins for two years: the previous year and the coming year, and fasting on 'ashûra, (the tenth day of Muharram) atones for the sins of previous years." ( Bukhari and Tirmidhi )

She has equally reported that Allah's apostle (peace and blessings of Allah be upon him) said:

"Four things the Messenger of Allah never neglected: Observing fast on the day of 'ashûra, 'Arafat, three days every month, and offering fajr sunnah prayers early in the morning." (Muslim)

These hadeeths proves that fasting on the day of Arafah, the day that precedes Eid Al-Adha was a lifelong practice of Muhammad (peace and blessings of Allah be upon him) as it has been reported by his wife.

There are reports that state that fasting on the day of Arafah is undesirable (Makruh). However, it is worth noting that this refers to the Hajj pilgrims who are performing the Hajj in the holy sites. If a person is performing the hajj, there is no fast for him or her on the day of Arafah as a blessing for him/her to ease the hardships of Hajj and to be more stronger to supplicate and perform the rites.

It has been reported that Umm al-Fadl, may Allah be pleased with her, sent milk to the prophet ( peace and blessings of Allah be upon him) and he drunk it on the day of Arafah.

"The companions doubted whether the Prophet (peace and blessings of Allah be upon him) was fasting on Arafah or not. She decided to prove to them that he was not, so she said, 'I sent to him milk, which he drank while he was delivering the khutbah (sermon) on 'Arafah.' " (Bukhari)

It undesirable (Makruh) that pilgrims fast on the day of Arafah and this is a mercy and a blessing for them, for fasting will undermine their powers and bbove all, they should not fast anyway for they are travelling.