Sahih Al Bukhari Hadith Number 758

Narrated Jabir bin Samura: Sa`d said, “I used to pray with them a prayer similar to that of Allah’s Messenger (peace be upon him) (the prayer of Zuhr and `Asr) reducing nothing from them. I used to prolong the first two rak`at and shorten the last two rak`at.” `Umar said to Sa`d “This was what we thought about you.”

10  Call to Prayers (Adhaan)
Hadith number 758
Volume no 1
Chapter: 95 (Recitation of the Qur’an (Surat Al-Fatiha) is compulsory for the Imam and the followers, at the home and on journey, in all As-Salat (the prayers) whether the recitation is done silently or aloud.)