Ibn 'Umar (Allah be pleased with them) reported
Allah's Messenger, (ﷺ) entered the House, and Usama, Bilal and Uthman b. Talha were with him, and they kept the door closed for a considerable time. Then it was opened and I was the first to enter the House and meet Bilal, and I said: Where did Allah's Messenger (ﷺ) observe prayer? He said: Between these two front pillars. I, however, forgot to ask him the number of rak'ahs that he observed.