Sahih Al Bukhari Hadith Number 795

Narrated Abu Huraira: When the Prophet (peace be upon him) said, “Sami`a l-lahu liman hamidah,” (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 (peace be upon him) used to say Takbir. He also used to say Takbir on rising after the two prostrations. (See Hadith No. 656).

10  Call to Prayers (Adhaan)
Hadith number 795
Volume no 1
Chapter: 124 (What the Imam and the followers say on raising their heads from bowing.)