Sahih Muslim
The Book of Prayers (Kitab Al-Salat)
Book Number: 004 / Hadith Number: 1164
'Abdullah b. Buhaina al-Asadi, the ally of Abual-Muttalib, reported: The Messenger of Allah (may peace be upon him) stood up in the noon prayer (though) he hadith sit (after the two rak'ahs). When he completed the prayer he performed two prostrations and said," Allah is the Most Great" in each prostration, while he was sitting before pronouncing salutation, and the people performed prostration along with him. That was a compensation for he had forgotten to observe jalsa (after two rak'ahs).