Sahih al-Bukhari Hadith 4289

Allah's Messenger (ﷺ) entered Makkah through its upper part and he was riding his she-camel. Usãma bin Zaid رضی اللہ عنہما was his Companion-rider behind him (on the same she-camel). In his company were Bilãl رضی اللہ عنہ and 'Uthmãn bin Talha رضی اللہ عنہ , who was one of the Al-Hajabah (who keep the key of the gate of the Ka'bah). When he made his she-camel kneel down in the Mosque (i.e., Al-Masjid al-Haram), he ordered him (i.e., 'Uthman) to bring the key of the Ka'bah. Then Allah's Messenger (ﷺ) entered the Ka'bah along with 'Usãma bin Zaid, Bilãl and 'Uthmãn bin Talha رضی اللہ عنہ , and he stayed in it for a long period and then came out. The people rushed (to get in) and `Abdullãh bin 'Umar رضی اللہ عنہما was the first to enter and he found Bilãl رضی اللہ عنہ standing behind the door. Ibn `Umar asked Bilãl, "Where did Allah's Messenger (ﷺ) offer the Salat (prayer)?" Bilãl showed him the place where he (ﷺ) had offered Salat (prayer). `Abdullah رضی اللہ عنہما later on said, "I forgot to ask Bilãl how many prostrations (i.e., Rak'a) the Prophet offered."