The Messenger of Allah (ﷺ) prayed Zuhr with two rak'ahs, then said the salam. They said: "Has the prayer been shortened?" So he stood up and prayed two rak'ahs, then he said the salam, then he prostrated twice.
Sunan an-Nasa'i Book 13, Hadith 49
← Previous Hadith "The Messenger of Allah (ﷺ) led us in praying 'Asr, and he said the salam after two rak'ahs. Dhul-Yadain stood up and said: 'Has the prayer been shortened, O Messenger of Allah (ﷺ) or did you forget?' The Messenger of Allah (ﷺ) said: 'Neither.' He said: 'One of them happened, O Messenger of Allah (ﷺ).' The Messenger of Allah (ﷺ) turned to the people and said: 'Is Dhul-Yadain speaking the truth?' They said: 'Yes.' So the Messenger of Allah (ﷺ) completed what was left of the prayer, then he prostrated twice when he was sitting after the taslim."

Sunan an-Nasa'i Book 13, Hadith 48 Next Hadith → The Messenger of Allah (ﷺ) prayed one day and said the salam after two rak'ahs, then he left. Dhul-Shimalain caught up with him and said: "O Messenger of Alah, has the prayer been shortened or did you forget?" He said: "The prayer has not been shortened, and I did not forget." He said: "Yes, by the One Who sent you with the truth." The Messenger of Allah (ﷺ) said: 'Is Dhul-Yadain speaking the truth?" They said: 'Yes.' So he led the people in praying two rak'ahs.

Sunan an-Nasa'i Book 13, Hadith 50