Sahih Bukhari

Narrated Anas bin Seereen:I asked Ibn `Umar, ""What is your opinion about the two rak`at before the Fajr (compulsory) prayer, as to prolonging the recitation in them?"" He said, ""The Prophet (ﷺ) used to pray at night two rak`at followed by two and so on, and end the prayer by one rak`ah witr. He used to offer two rak`at before the Fajr prayer immediately after the Adhan."" (Hammad, the sub-narrator said, ""That meant (that he prayed) quickly."")