Sahih Al Bukhari Hadith Number 784

Narrated `Imran bin Husain: I offered the prayer with `Ali in Basra and he made us remember the prayer which we used to pray with Allah’s Messenger (peace be upon him). `Ali said Takbir on each rising and bowing.

10  Call to Prayers (Adhaan)
Hadith number 784
Volume no 1
Chapter: 115 (Itmam At-Takbir (i.e., to end the number of Takbir or to say the Takbir perfectly) on bowing. [See Fath Al-Bari])