Voluntary fasting in the month of Thul-Hijjah is permissible for the pilgrim
14-9-2009 | IslamWeb
Question:
Is it permissible for the pilgrim to observe voluntary fasting in the course of his Hajj?
Answer:
All perfect praise be to Allaah, the Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is permissible for the pilgrim to observe voluntary fasting during the first ten days of Thul-Hijjah as well as the days prior to Thul-Hijjah. Like others, this is recommended for him - except the day of ‘Arafah (the 9th day of Thul-Hijjah) as it is an act of Sunnah for the pilgrim to abandon fasting on that day.
In his "Al- Umm", Ash-Shaafi‘i 
said, "I recommend fasting that day (the day of ‘Arafah), unless one is performing Hajj. In that case, I recommend him not to fast because he is a traveler and is already offering a sacrifice. Also, the Prophet, sallallaahu ‘alayhi wa sallam, abandoned fasting on that day when he was performing Hajj. One should also do so (not fast) in order to be able to supplicate to Allaah during that day, as the best supplication is that on the day of ‘Arafah."
As for fasting the 10th day of Thul-Hijjah, it is prohibited for the pilgrim as well as for others.
The obligatory fasting for the pilgrim who cannot afford a sacrificial animal, which is to fast three days, should be observed in the course of Hajj. Allaah The Exalted Says (what means): {And whoever cannot find [or afford such an animal] - then a fast of three days during Hajj and of seven when you have returned [home]. Those are ten complete [days].}[Quran 2: 196] Many scholars are of the view that it is permissible for such a pilgrim to observe the obligatory fasting of these days during the days of Tashreeq (the 11th, 12th and 13th day of Thul-Hijjah). However, when fasting is not obligatory, the pilgrim is not permitted to fast on these days.
Allaah Knows best.