Sahih Bukhari Volume 001, Book 012, Hadith Number 761.
Narated By Abu Huraira : When the Prophet said, "Sami' a-l-lahu Liman hamida," (Allah heard those who sent praises to Him), he would say, "Rabbana wa-laka-l-hamd." On bowing and raising his head from it the Prophet used to say Takbir. He also used to say Takbir on rising after the two prostrations. (See Hadith No. 656).