And He, exalted is He, also says: “If you dispute about anything, refer it back to Allah and the Messenger, if you truly believe in Allah and the Last Day; that is better and gives the best resolution.” (59) [Al-Nisāʾ 4:59]

Now we and you have differed over this issue. Whichever of the two views the Quran and the Sunnah uphold we shall accept, and we will not abandon what they require for the sake of anyone’s opinion. On this basis we say: the evidence from the Sunnah(1) for stipulating a muḥallil consists of several points.

First: the report transmitted by the Guardian-Scholar of the Ummah, Muḥammad ibn Shihāb al-Zuhri, from the most learned of the Followers, Saʿīd ibn al-Musayyib, from the preserver of Islam, Abū Hurayrah, who said that the Messenger of Allah ﷺ declared: “Whoever sends a horse to run between two horses while he is not confident that it will not be beaten—there is no harm; but whoever sends a horse to run between two horses while he is sure it will not be beaten—that is gambling.”(2)

The Imam of the people of the Sunnah, Aḥmad ibn Ḥanbal, recorded it in his Musnad from Yazīd ibn Hārūn—Sufyān ibn Ḥusayn—from al-Zuhri; on the strength of this report he based his legal ruling and acted upon it.