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.)"
Sahih al-Bukhari Book 14, Hadith 6