It was recorded by Aḥmad (4/315) [who] narrated to us through ʿAbd al-Raḥmān ibn Mahdī, who narrated to us through Sufyān from Yazīd ibn Abī Khālid with it. And this Yazīd is Ibn ʿAbd al-Raḥmān Abū Khālid al-Dalānī. The ḥāfiẓ said: "He is truthful but makes many mistakes and used to practice tadlīs." I said: someone like him does not oppose the narrations of al-Masʿūdī and Abū Ḥanīfah, for their narrations are more reliable. This is supported by what was recorded by al-Ḥākim (4/196) through the path of Abū Qilābah ʿAbd al-Malik ibn Muḥammad al-Raqāshī, who narrated to us through Abū Zayd Saʿīd ibn al-Rabīʿ, who narrated to us through Shuʿbah from al-Rukayn ibn al-Rabīʿ from Qays ibn Muslim from Ṭāriq ibn Shihāb from ʿAbd Allāh in a marfūʿ form with the wording: "Allāh has not sent down a disease except that He has also sent down a cure for it, and in the milk of cows there is a cure for every disease." He said: "Authentic according to the conditions of Muslim." Al-Dhahabī agreed with him. However, what they said requires scrutiny, for its narrators are according to the conditions of Muslim except for al-Raqāshī. Moreover, he is weak in memory. The ḥāfiẓ said: "He is truthful but makes mistakes, his memory has changed." I said: someone like him is used as evidence when he agrees with others, but not when he contradicts or is unique. Here, he is unique in saying: "a cure for every disease." Al-Rabīʿ ibn al-Rukayn narrated it from Ibrāhīm ibn Muhājir from Qays ibn Muslim with it, and its wording is: "Seek treatment with the milk of cows, for I hope that Allāh will make it a cure, for they eat from the trees." It was recorded by al-Ṭabarānī (3/49/1). Al-Rabīʿ ibn al-Rukayn is al-Rabīʿ ibn Sahl ibn al-Rukayn ibn al-Rabīʿ ibn ʿUmaylah al-Fazārī, and he is weak by consensus. He is the grandson of al-Rukayn ibn al-Rabīʿ who is in the isnād of al-Ḥākim, and he is on..