Musnad Ahmad 27:1559

Ishaq narrated to me, Layth and Hashim narrated to us, they said: Layth narrated to us, Ibn Shihab narrated to me, from Salim, from his father, who said: The Messenger of Allah, peace and blessings of Allah be upon him, entered the House (the Kaaba) along with Usama ibn Zayd, Bilal, and Uthman ibn Talha al-Hajabi, and they closed the door upon themselves. When they opened it, I was the first to enter. I met Bilal and asked him, "Did the Messenger of Allah, peace and blessings of Allah be upon him, pray inside it?" He said, "Yes, between the two Yemeni pillars." Hashim said: He prayed between the two pillars.