Musnad Ahmad 718:1

Waki’ narrated to us, Sufyan narrated to us, from Zayd ibn Aslam—Sufyan said once: from Busr or Bishr ibn Mihjan, then he would say afterwards: from Ibn Mihjan al-Dayli, from his father, who said: I came to the Prophet, peace and blessings of Allah be upon him, while he was in the mosque, and the prayer time arrived, so he prayed. He then said to me, "Did you not pray?" I said, "O Messenger of Allah, I have already prayed in my dwelling, then I came to you." He said, "If you have done so, then pray with them, and make it a supererogatory (nafilah) prayer." My father said: Abu Nu’aym and ‘Abd al-Rahman did not say: "and make it a supererogatory prayer."