It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) prayed three rak'ahs and then concluded with the salam. So Dhu al-Shimalayn said: O Messenger of Allah! Has the prayer been shortened? The Prophet (peace and blessings be upon him) said: "Is it so, O Dhu al-Yadayn?" He said: Yes. So the Prophet (peace and blessings be upon him) prayed one rak'ah and performed two prostrations.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11759