It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Do not abandon the two Sunnah (units) of Fajr, even if horses trample over you.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 9253
Hadith Gradingحکم دارالسلام:إسناده ضعيف لجهالة ابن سيلان