Sahih Bukhari
Pilgrimmage (Hajj)
Volume: 002 / Book Number: 026 / Hadith Number: 719
Narrated 'Abdullah bin Masud:
I offered (only a) two Rakat prayer with the Prophet (at Mina), and similarly with Abu Bakr and with 'Umar, and then you d offered in opinions. Wish that I would be lucky enough to have two of the four Rakat accepted (by Allah).