Ahmad recorded it (4/315): “ʿAbd al-Raḥmān ibn Mahdī narrated to us; Sufyān narrated to us, from Yazīd ibn Abī Khālid,” with the same chain. This Yazīd was Yazīd ibn ʿAbd al-Raḥmān, Abū Khālid al-Dālānī. Al-Ḥāfiẓ said: “He was truthful, made many mistakes, and practised concealment in transmission.”

I say: A narrator such as him cannot outweigh the two reports of al-Masʿūdī and Abū Ḥanīfah; their report is more preponderant. This is further supported by what al-Ḥākim recorded (4/196) through the route of Abū Qilābah ʿAbd al-Malik ibn Muḥammad al-Raqqāshī: Abū Zayd Saʿīd ibn al-Rabīʿ narrated to us; Shuʿbah narrated to us, from al-Rukayn ibn al-Rabīʿ, from Qays ibn Muslim, from Ṭāriq ibn Shihāb, from ʿAbdullāh, in a report attributed to the Prophet: “Allah has not sent down any disease without also sending down for it a cure, and in cows’ milk there is a cure for every disease.”

He said: “Authentic according to Muslim’s criteria,” and al-Dhahabī concurred with him.

However, their assessment is open to question, for its narrators meet Muslim’s criteria apart from al-Raqqāshī. Moreover, he had poor retention. Al-Ḥāfiẓ said: “He was truthful, made mistakes, and his memory changed.”

I say: A narrator such as him may be relied upon when he agrees with others, but not when he contradicts them or relates something alone. Here, he alone reported the wording: “a cure for every disease.” Al-Rabīʿ ibn al-Rukayn also narrated it from Ibrāhīm ibn Muhājir, from Qays ibn Muslim, with the same chain, with the wording: “Seek treatment with cows’ milk, for I hope that Allah has placed healing in it, since they eat from the trees.” Al-Ṭabarānī recorded it (3/49/1).

Al-Rabīʿ ibn al-Rukayn was al-Rabīʿ ibn Sahl ibn al-Rukayn ibn al-Rabīʿ ibn ʿUmaylah al-Fazārī. He is unanimously considered weak, and he is the grandson of al-Rukayn ibn al-Rabīʿ, who occurs in al-Ḥākim’s chain, and he is, despite—