Allah's Messenger (ﷺ) came to Mecca through its higher region on the day of the Conquest (of Mecca) riding
his she-camel on which Usama was riding behind him. Bilal and `Uthman bin Talha, one of the
servants of the Ka`ba, were also accompanying him till he made his camel kneel in the mosque and
ordered the latter to bring the key of the Ka`ba. He opened the door of the Ka`ba and Allah's Messenger (ﷺ)
entered in the company of Usama, Bilal and `Uthman, and stayed in it for a long period. When he
came out, the people rushed to it, and `Abdullah bin `Umar was the first to enter it and found Bilal
standing behind the door. He asked Bilal, "Where did the Prophet (ﷺ) offer his prayer?" He pointed to the
place where he had offered his prayer. `Abdullah said, "I forgot to ask him how many rak`at he had
performed."
Sahih al-Bukhari Book 56, Hadith 197