Sahih Al Bukhari Hadith Number 1068

Narrated Abu Huraira: On Fridays the Prophet (peace be upon him) used to recite Alif Lam Mim Tanzil-As-Sajda (in the first rak`a) and Hal ata `alal-insani i.e. Surat ad-Dahr (LXXVI) (in the second rak`a), in the Fajr prayer.

17  Prostration During Recital of Qur’an
Hadith number 1068
Volume no 2
Chapter: 2 (To prostrate during the recitation of Salat Tanzil – As-Sajda (No. 32)