The Ruling on the Hajj Pilgrim Shortening the Prayer
Question:
What is the ruling on the Hajj pilgrim shortening his prayers during his stay for more than four days in Makkah?
Answer:
If the residence of the pilgrim in Makkah is for four days or less, then the Sunnah is for him to pray the four-Rakah prayers as two Rakahs, according to the action of the Prophet (sallallaahu alaihi wa sallam) in the Farewell Pilgrimage. However, if he intended to stay for more than four days, then it is better for him to pray them as four, which is the view of the majority of the scholars.
Source:
Shaykh `Abdul-`Azeez Bin Baz
Fatawa Islamiyah Vol. 2 Page 429