Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Bukhari :: Book 5 :: Volume 59 :: Hadith 683
Narrated (Abdullah) bin 'Umar:
The Prophet arrived (at Mecca) in the year of the Conquest (of Mecca) while Usama was riding behind him on (his she-camel)'. Al-Qaswa.' Bilal and 'Uthman bin Talha were accompanying him. When he made his she-camel kneel down near the Ka'ba, he said to 'Uthman, "Get us the key (of the Ka'ba). He brought the key to him and opened the gate (of the Ka'ba), for him. The Prophet, Usama, Bilal and 'Uthman (bin Talha) entered the Ka'ba and then closed the gate behind them (from inside). The Prophet stayed there for a long period and then came out. The people rushed to get in, but I went in before them and found Bilal standing behind the gate, and I said to him, "Where did the Prophet pray?" He said, "He prayed between those two front pillars." The Ka'ba was built on six pillars, arranged in two rows, and he prayed between the two pillars of the front row leaving the gate of the Ka'ba at his back and facing (in prayer) the wall which faces one when one enters the Ka'ba. Between him and that wall (was the distance of about three cubits). But I forgot to ask Bilal about the number of Rakat the Prophet had prayed. There was a red piece of marble at the place where he (i.e. the Prophet) had offered the prayer.