Characteristics of Prayer
Bukhari :: Book 1 :: Volume 12 :: Hadith 792
Narrated 'Abdullah bin Buhaina:
(he was from the tribe of Uzd Shan'u'a and was the ally of the tribe of 'Abdul-Manaf and was one of the companions of the Prophet): Once the Prophet led us in the Zuhr prayer and stood up after the second Rak'a and did not sit down. The people stood up with him. When the prayer was about to end and the people were waiting for him to say the Taslim, he said Takbir while sitting and prostrated twice before saying the Taslim and then he said the Taslim."