Musnad Ahmad 33:950

Muhammad ibn Bakr narrated to us, Ibn Jurayj informed us, 'Amr ibn Dinar informed me that he heard Jabir ibn 'Abd Allah saying: A man came while the Prophet, peace and blessings of Allah be upon him, was on the pulpit on Friday delivering the sermon. The Prophet, peace and blessings of Allah be upon him, said to him: "Have you prayed two rak'ahs?" He said: "No." He said: "Then pray."