Sunan Ibn Majah, Chapter: The Chapters of Establishing the Prayer and the Sunnah Regarding Them

"The Messenger of Allah (saw) said the Salam after three Rakah for 'Asr, then he stood up and went into the apartment. Khirbaq, a man with big hands, stood up and called out: 'O Messenger of Allah! Has the prayer been shortened?' He came out angrily, dragging his lower garment, and asked about it, and was told (what had happened). So he performed the Rakah that he had omitted, then he said the Salam, then he prostrated twice and said the Salam again." Hasan