Musnad Ahmad 27:1098

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Simak, I heard Ibn 'Umar saying: "The Messenger of Allah (ﷺ) prayed inside the House (the Ka'bah)." And there will come those who will forbid you from it, so you will hear from him—he said: meaning Ibn 'Abbas—and Ibn 'Abbas was sitting near him.