Musnad Ahmad 27:1672

Ya'qub narrated to us, my father narrated to us, from Ibn Ishaq, Nafi' narrated to me, from Ibn Umar, "That the Messenger of Allah, may Allah bless him and grant him peace, prayed when he arrived returning from his Hajj in that valley." He said: "Then the Messenger of Allah, may Allah bless him and grant him peace, entered Medina, and he made his camel kneel at the door of his mosque, then he entered it, and he performed two rak'ahs in it, then he departed to his house." Nafi' said: "And Abdullah ibn Umar used to do likewise."