Musnad Ahmad 941:38

Abu Mu’awiyah narrated to us, al-A’mash narrated to us, from ‘Umarah, from Abu al-Sha’tha’, who said: I went out for Hajj and entered the House (the Ka’bah). When I was by the two pillars, I proceeded until I was touching the wall. He said: Ibn ‘Umar came and stood beside me and prayed four [rak’ahs]. He said: When he finished praying, I said to him: "Where did the Messenger of Allah, peace and blessings of Allah be upon him, pray in the House?" He said: He said: "Right here. Usamah ibn Zayd informed me that he prayed here." He said: I said: "How many did he pray?" He said: "Regarding this, I find myself blaming myself that I stayed with him for a lifetime, then I did not ask him how many he prayed." He said: When the following year came, he said: I went out for Hajj. He said: I came to his place [of prayer]. He said: Ibn al-Zubayr came and stood beside me, and he did not cease pushing against me until he moved me out of it, then he prayed four [rak’ahs] in it.