Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: the Messenger of Allah (peace and blessings be upon him) led us in prayer and then went inside. Some of the people said to one another: Has something been added to the prayer? He (peace and blessings be upon him) said: "What is that?" (A man) said: You (peace and blessings be upon him) prayed five rak'ahs. So he (peace and blessings be upon him) took him by the hand and went out to the mosque, where there was a circle in which Sayyiduna Abu Bakr and Sayyiduna Umar (may Allah be pleased with them both) were also present. He (peace and blessings be upon him) said: "Is what Dhu al-Yadayn says true?" They said: Yes, O Prophet of Allah. So he (peace and blessings be upon him) turned to face the qiblah and performed two prostrations.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9818