Musnad Ahmad 31:678

Hassan narrated to us, Ibn Lahi'ah narrated to us, from Musa ibn Wardan, from Abu Sa'id al-Khudri, that he said: We were with the Messenger of Allah, may Allah bless him and grant him peace, on a Friday. A Bedouin entered while the Messenger of Allah, may Allah bless him and grant him peace, was on the pulpit, and the Bedouin sat at the back of the people. The Prophet, may Allah bless him and grant him peace, said to him: "Have you prayed two rak'ahs?" He said: "No." He said: "So he commanded him, and he came to the open space that was by the pulpit, and he prayed two rak'ahs."