Menurut versi Ibn[[Ibnu Ishaq]] (w.767), [[al-Waqidi]] (w.823) dan Sa'id ibn Abd al-Aziz al-Tanukhi (fl.c.800) yang berbasis di Suriah, yang merupakan versi umumnya diikuti oleh [[Ya'qubi|al-Yaqubi]] (w. 897), Pertempuran Fahl terjadi pada tanggal 13 Dzulqadha Hijriah (634 Desember atau Januari 635 M).<ref>Donner 1981 , hal. 128, 130.</ref> The other common version among the Muslim sources was that transmitted by Sayf ibn Umar (d. 786–809) from the Syria-based Abu Uthman Yazid ibn Asid al-Ghassani, as well as Abu Haritha ibn Abshami and others, all of whom obtained their information from one of two earlier sources, who were known only as Khalid or Ubada. In this version of events, the date of the Battle of Fahl is not provided, only that it occurred after the fall of Damascus, which this version places in Shawwal 14 AH (November or December 635).<ref>Donner 1981, pp. 134, 137</ref>
