Sunan An-Nasai, Chapter: The Book of the Adhan (The Call to Prayer)

that the Messenger of Allah (saw) prayed one day and said the Taslim when there was still a Rakah left of the prayer. A man caught up with him and said: 'You forgot a Rakah of the prayer!' So he came back to the Masjid and told Bilal to call the Iqamah for prayer, then he led the people in praying one Rakah. I told the people about that and they said to me: 'Do you know who that man was?' I said: 'No, not unless I see him.' Then he passed by me and I said: 'This is he.' They said: 'This is Talha bin Ubaidullah.'" (Sahih)